Portable Apps for Microsoft Windows
Install these anywhere, even on a thumb drive. No more junk scattered all over your system. These programs' files are all in one place, so they can be run from a portable drive on any Windows computer. To uninstall, just unplug, or delete the installation directory.
More information (and apps) can be found at http://portableapps.com/apps. These are just the ones I find most useful.