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]

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.

Well, that sure didn't take long.

Just days ago Mozilla posted a few conceptual images displaying a new default theme for Firefox 3.7. Thanks to DeviantArt user Boneyard Brew and his friends, you can now tweak your existing Firefox 3 install (provided you're not running 3.6) look pretty dang close to the mockups.

You'll need to grab a couple things to pull off the transformation:

• Personal Menu - One of my favorite add-ons. Needed to combine the bookmark and tools icons.
• All Glass - To add Vista / Windows 7 Aero Glass effects to the toolbars
• Stylish - To apply the provided UserStyle which tweaks inactive tab text
• The theme .JAR, from DeviantArt (of course)

The end result is pretty faithful to the mockup. Pull the switcheroo and confuse your pals - tell them you got your hands on an early pre-alpha (Make it more convincing with a quick Titlebar Tweak)!

[via Tweaking with Vishal]

One of the best things about Tumblr as a blog platform is how easy it is to try out new themes on your Tumblog. There's a wide selection of built-in themes, some of which are excellent, and many more that you can find elsewhere on the web and plug in with a quick copy-and-paste. Just go to http://www.tumblr.com/customize, turn on custom HTML, and plug in the code for your chosen theme, which you can usually find at the designer's page. Here are ten of my favorites to get you started:

Windows Mobile users have been able to choose themes for their home screen, start menu, and toolbars for years. But usually Windows Mobile phones and PDAs come with just a handful of backgrounds and themes to choose from. It looks like Microsoft plans to spruce things up a bit by offering a number of designer themes for Windows Mobile 6.5 from actual designers including Isaac Misrahi, Ron Arad, and Vera Wang.

Blogger Long Zheng has posted a series of pictures of the new designer themes, ripped from a pre-release version of Windows Mobile 6.5. And while I can't promise that you're going to find them all particularly attractive, they'll definitely give Windows Mobile phones a bit of flare.

You can find 4 more themes and higher resolution images at I Started Something.

When Google introduced themes for Gmail, users who run Google Apps on their own domains figured it would just be a matter of time before they got themes too. After a few months of anticipation -- and frequent postings on message boards, Google Groups, and even Yahoo! Answers -- their wish is finally granted. Themes for Google Apps have now started rolling out.

Not all users have themes yet -- my own domain included -- but here's where to look to enable them. In Gmail for Google Apps, open settings and look for the themes tab on the far right. If you have themes, it should be there. If you don't yet, be patient. After all, we've waited quite a while, and a few more days aren't going to matter that much. Taking a tip from Lifehacker, here's a direct link to the themes page, to make it easier for you to check: https://mail.google.com/a/yourdomain.com/#settings/themes Just replace "yourdomain.com" with your actual domain name.

Thanks to all the readers who tipped us off about this.

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.

First they rolled out themes, now Google has decided to give us free reign over the look of our Gmail inbox.

That's right, you're no longer limited to Google's 31 pre-made themes - you can now fully customize your color scheme. The template allows you to choose colors via a panel of presets, or you can click the + symbol to access the full range of available colors. The preview updates instantly as you make your color choices.

Once you've got things set up the way you like them, just click save and close and your new design will be applied.

[ via Google Blogoscoped ]