Dropbox has gone public, opening it's file sharing and backup services to the public. The cross-platform tool makes it easy for users of multiple computers and operating systems to keep their files safely backed up and in sync.

Brad first posted about Dropbox in March, and the development team has been hard at work ever since.

Once you've uploaded a file, the software is smart enough to upload only the changes. For anyone who has an ISP with a ridiculous upload cap (30k/s for me) it's a welcome feature, since it means I won't be uploading a 75 megabyte PSD over and over. It also makes sharing work with my Mac-using partner a snap.

The web interface - "Now with lots of Ajax!" according to Dropbox - has seen a number of improvements. It handles multiple uploads nicely, and makes accessing and storing files a breeze even when you're not using the desktop client.

You can view a screencast of the service, or take the old-fashioned tour if you'd prefer.

Dropbox is feature packed, gives you 2 gigabytes of free, online storage, and is definitely one of the better services available.