Even though I've read many articles at Lifehacker about all the cool things you can do with a thumbdrive, I find myself not doing a whole lot more than using it as a basic file storage device. I think part of the problem is that I use a Mac at home and a PC at work, and many of these "cool tricks for thumbdrives" don't do cross platform very well.
DemocraKey, for example, works on PC, but not on Mac. (Truth be told, I can't get DemocraKey to autorun on my PC, either, but that might be the result of security policies from my workplace.) Likewise, there are portable/thumbdrive apps for the Mac OS X only platform that become nothing more than wasted space when you plug that thumbdrive into a Windows PC.
There are plenty of Java apps out there-- is it so hard to believe that something like DemocraKey might have been done in Java, and thus be cross platform?