Portable Linux Apps
Back in the days when I was still a Windows user, portable apps where a good way of carrying current versions of my favorite tools with me on a USB stick. Now, this is also possible on most Linux variants with Portable Linux Apps.
There are already more than 50 apps you can put on your USB stick, just remember to make them executable. This is not only great if you want to run the application on any desktop, but it also comes in handy if you want to test out a nightly build without really installing it on your system. The latter remains stable, while the former hast got everything it needs to run contained in itself.
If you run into trouble there's a forum, too, where you can ask for help or request a new package - however there's not much happening there yet. But since everything is so dead easy, it should just work. At least on Ubuntu 10.04, OpenSUSE 11.2, and Fedora 12. You might want to use a LiveCD of one of these distributions if you're on a different system.