OK, this is beyond useless, but cool. I recently read this article
and thought the idea of seeing through your workspace was cool. Sure, you could use this to collaborate, but why not use it to make web browsing or email, or writing a letter a little bit more exciting? So I looked around here for how to create transparent windows and found Windowshade
. Now, I have the itunes visualizer going in the background (or sometimes a DVD), with a transparent Safari or Word Processor or Email window (created by WindowShade when I double-click the title bar) on top. It really is amazing how you can switch attention between the two. And nothing is more soothing than having your web pages "flow." Of course, this may cut your productivity or cause epilspsy :-) Still, it is cool and a testament to the power of Quartz.
Incidentally, this hint was also neat, but this method allows for a wider range of applications, layers, diversions, and let's you set the degree of transparency (really important in finding the balance between cool and usable).