Growl provides customizable pop-up alerts for hundreds of Mac apps, making sure you never miss an important chat message or completed download. You can use Growl to set an alert for just about anything, and you can also make Growl notifications look practically any way you want. The built-in themes and the list on the official Growl Styles page don't even begin to cover all the options for gorgeous notifications, from the minimal to the very flashy.

Here are 10 lesser-known Growl styles that look a lot nicer than the defaults:

A lot of new Ubuntu users are put off by the default color scheme. "Brown and orange? Those are colors a non-winning football franchise would pick." (you know I love you, Browns!) Well, it's really not all that hard to tweak your interface to something more "you" in Ubuntu -- and soon there will be some more default options available.

Four new community-developed themes are now available, and they're all well done and visually appealing. While there are still plenty of mocha tones, I think each one is a nice alternative to Ubuntu's out-of-the-box look.

Check the screens and get download links after the break!

[via Ubuntu Manual]

Not long ago a DeviantArt user put together a Firefox 3/3.5 theme based on Mozilla's concept for Firefox 3.7. Want to go the extra .3 and jump ahead to version 4? Take a look at Strata40.

By using the them in conjunction with a few Firefox addons - All Glass, Personal Menu, Fission, Omnibar, and Stylish - and following some lengthy but simple instructions you'll have yet another slick, futuristic look for your browser. The complete rundown is available on SpewBoy's DevArt page. I didn't adhere strictly to the 4.0 look (I added bookmarks and downloads buttons), but you're free to tweak the layout to your liking.

As before, don't forget to change the FF window title text using Titlebar Tweak or Nightly Tester Tools to make the illusion even more believable. You'll need NTT anyway to get the theme working on Firefox 3.6, so you may as well have some fun with it.

[via Tweaking with Vishal]

Enigma itself has improved by partnering with Rainmeter. There's now a quickstart wizard so you can set up the theme without editing text files, and Enigma can take advantage of some of the new features in Rainmeter, including iTunes and wifi plugins. Also, the new Rainmeter is fully compatible with Windows Vista and Windows 7. Now anybody can set up a well-designed desktop mod without having to edit a single file in a text editor.

Just a few days after being spotted in Chrome's new tab page, the official Google Theme Gallery is now open for business.

Am I really going to stick with the grass theme? Probably not, but I was in the mood after finishing up my yardwork this evening. There are currently 29 different skins available.

As with other theme galleries, not all of the options are going to win a GUI beauty contest. Some of them (like Legal Pad - check it after the break) might make you do a spit take. There are, however, some interesting options. At the very least, maybe this will help spell the end of bothersome Chrome skinning that involves backing up the default.dll and restoring it after Chrome crashes due to an incompatible skin.

Some of the themes - like Dots, also pictured after the break - even bleed past the bookmarks toolbar on the new tab page. The download and history pages, however, are kept clean below the divide. Thank god, because that would be a little more than I could take.

Remember, you'll need to be running the Chrome 3 beta or developer channel or be using a recent build of Chromium to get in on the fun. If that includes you, check 'em out then tell us which one you're switching to in the comments. Unless you're not impressed with the selection, in which case - sound off!

After all this "make your Firefox look like Chrome" nonsense, I'm holding out for the Firefox skin - just so I can post confusing screenshots.

[via Google OS]

No, I'm not kidding. I wish I was, but the truth is that a DeviantArt user has cobbled together a skin for Windows that gives it a Google Chrome-y look. And think Chrome on XP - without the sex appeal you get with Aero Glass.

Thick, powder blue borders? Check.

The Chrome logo replacing the start orb? Check.

The comments on DevArt are all very positive, though I'm personally going to pass on this one. I'm just not a big fan of all that blue.

But hey, if you're miffed by the fact that Chrome on XP doesn't look consistent with your other application windows at least now you can apply the Google dress code to them.

A number of other blogs are calling this a "Google Chrome OS Transformation Pack." That'd be a pretty amazing feat, since we only have 1) questionable leaked images to go by and 2) they appeared two weeks after the creator posted this theme to DevArt.

Hell is other people's iGoogle themes. I love the custom Google homepage as much as the next person, but the selection of user-submitted themes is, frankly, atrocious. The list ranges from photos of Angelina Jolie to photos of some guy's dog, with very few options that actually hold up over weeks and months of being in your face whenever you open a new browser window. Instead of subjecting you to the worst of the worst -- maybe we'll save them for a Fugly Friday -- I've collected my top 10 well-done iGoogle themes.

We love customization around here. Computers would be a sad, sterile place without being able to alter, to any degree, your workspace. Applications often provide "skins" for various reasons (usually just for fun). But the skins that provide a cool theme can also turn a workspace ugly in a hurry. In this case beauty is often in the eye of the beholder. Just as with clothes, there are plenty of skins out there I wouldn't put on my download queue, let alone my apps.

I'm going to leave full-on OS mods alone this round (with one notable exception of abandonware below). I'm sure everyone is familiar with WindowBlinds, etc.

Windows Media Player
The default UI is pretty bland, so MS has an enormous well of skins to choose from. I'm not sure what percentage of skins are marketing tools, but it looks like a pretty good number. Still, the sheer variety from amazing to totally fugly is staggering.

Coolplayer
There's definitely something to be said for bland, because Coolplayer's default skin is hideous. Red, orange and moldy tomato are not good color choices, nor is the wacky text layout which you should simply glance at for info. Lucky the thing is a nice player, I guess. I could keep listing music players with skins, but I'll leave them alone. Once you open that door, any kid with Paint can come along and thrash your look and feel. Maybe that's why OS X makes it so hard to radically change the look?

Kaleidescope
Speaking of Mac OS, this classic Mac OS goodie was a favorite of mine back in the pre-OS X days. There was an amazing variety of themes, and while I don't want to dwell on OS mods, I think Kaleidescope is a good example of the variety of artistry you find whenever customization is allowed. Still, while I love Masashi Ichikawa's work, I don't think I'd take a business client seriously if I saw their OS looking like KidPaint.

Firefox
Well, of course! Not only does FF let you customize the look, you can extend the functionality of the browser with add-ons, which also alters the look and feel. Version 3 of Firefox changed things a bit, but Mashable did a nice piece last year featuring the top 20 themes still compatible with v.3. I tend to use the default, as Foxlite (its name) works very well and keeps RAM issues to a minimum.

I absolutely love the popular Mac multi-chat app Adium. Not only does it support a large number of messaging protocols -- including Facebook Chat in the latest version -- it's insanely customizable. In Adium, you can change the look of everything from your contact list to your message style to your dock icon. There's an extensive library of user-created styles at AdiumXtras.com, but they're not all good.

Recently, I went on a bit of a downloading tear, rummaging through the Adium Xtra trash to discover the Adium Xtra treasure. Here, I present my findings: 8 of the slickest, most beautiful add-ons ever to grace a chat client. To check out the full range of Adium Xtras for yourself, go to adiumxtras.com.

Message Style: Cinematic

Cinematic is a smooth, dark style that fits in really well with OS X. It sports Apple's signature "reflection" effect, and uses buddy icons to show who's talking -- no text necessary. I like an uncluttered feeling when I'm chatting, and Cinematic delivers. Match it up with a darker buddy list style and wallpaper for a really put-together desktop.

It's been a few years since the Opera web browser's interface got a major overhaul. But now the Opera Desktop Team has posted an updated version of Opera 9.5 beta which features a shiny new theme.

The new theme is a bit closer to what you'll find on Opera's non-desktop browsers, including Opera 9.5 for Windows Mobile and Opera for the Nintendo Wii. Aside from a darker look, there are a few nice features, like an animated stop/refresh button that turns red when a page is loading, and green when it's finished.

There's also a new settings icon in the main toolbar that lets you open the side panel to launch the Opera Widget engine, bookmark sidebar and other tools.

The updated version of Opera 9.5 beta is a development snapshot, so there are some known issues. But there's an option to install this version side by side with an existing version of Opera so you don't lose your settings.

After checking out 10 slick new themes for NetNewsWire yesterday, we started going on a themes kick. Many of our favorite applications, from VLC to Firefox are skinnable. Today, let's take a look at chat and social networking application Digsby.

Digsby already ships with a decent looking set of skins. But if you'd prefer Digsby to look like Windows Live Messenger, or a native OS X application (even though Digsby doesn't currently run on OS X), you can install user-generated skins.

Digsbies.org has a list of skins available, plus a series of conversation themes and emoticon sets. The site is an unofficial Digsby community, don't expect to get tech support updates from the Digsby team at Digsbies. But you can find a wealth of information at the Digsbies wiki, IRC channel, and blog. There's also a Digsby wish list where you can vote for the features you'd most like to see in future releases. The actual developers may or may not ever actually read your comments or pay attention to your vote. But if you have something you really want to get off your chest, Digsbies could be the place to do it.

[via Techie Buzz]

A few months ago Google launched an iGoogle themes gallery, making it a little easier to find themes for your personalized Google homepage. But just a little. While you can search for themes in the directory, there's no way to browse by category. So if you want to see celebrity, nature, or artsy themes, you have to either search through the whole pile or keep entering search terms until you find what you're looking for.

InThemes is a new unofficial iGoogle themes gallery that puts the official gallery to shame. Themes are divided up into categories and subcategories. And since each theme submitted to inThemes is reviewed before it's added to the gallery, there's a better chance of finding themes that aren't... how to put this delicately... hideous.

[via Google Blogoscoped]

If you love Ubuntu Linux, but you're not so fond of its default brown theme, there's hope. You can find an assortment of alternate themes in the System->Preferences->Appearance menu. The themes will change the colors of your program toolbars.

But if you're looking for something slightly more comprehensive, you might wan to check out Blubuntu. It's a theme that gives Ubuntu a nice calm blue color scheme. It also comes with a suggested wallpaper.

You can install Blubuntu by opening a terminal window and typing "sudo apt-get install blubuntu-look." Once installed, you should find Blubuntu listed in your Appearance menu. In order to apply Blubuntu to your login screen, go to System->Administration->Login Window, and select Blubuntu from the "local" tab.

[via Tombuntu]

Count this as the newest entry in the mind-boggling "I have a PC but I want to make it look like a Mac" trend.

Apple Live Messenger is a skin for Windows Live Messenger that will magically transform your Messenger windows into an Apple look-alike. The new Messenger interface comes complete with Apple logo, Aqua Blue background, and much more Apple-y goodness.

Proof that we are all Apple fanboys in our core (pun definitely intended), the Apple Live Messenger skin is currently the third most popular skin on the Messenger Plus! Live website, with over 200,000 downloads.

Installing the skin requires Windows Live Messenger and Messenger Plus! Live, both free downloads. In case you're not familiar, Messenger Plus! Live is a popular add-on for Windows Live Messenger that adds a number of features and extras to the software.

[via Appaholic]