I have no idea whether using the keyboard is more likely to ward off repetitive stress injuries than using the mouse, but I just discovered Launchy from a Lifehacker post yesterday, and it is pretty sweet.
Launchy is a lightweight application launcher for Windows. It keeps track of your start menu, your Firefox bookmarks (I disabled this, as I have too many bookmarks and they were overwhelming my programs), and the contents of any any other folder you like (like your IE Favorites folder). Hit Alt-Space (re-configurable) to bring up the tiny window: start typing the name of the program you want to open, and hit Enter when it appears.
It also does simple calculations, so forget hunting for the calculator or using the command line. Just hit your hotkey and type in your problem. Same goes for the major search engines. ‘Google:searchphrase’ is all you need. Definitely faster if your browser isn’t already out.
At first, it felt cumbersome. But after disabling the bookmarks feature (just change the /plugins/foxy.dll file name to foxy.ddl so you know where to find it if you want it again) and changing the hotkey to Ctrl-Space, I am realizing just how much time I was wasting mousing through the Start Menu.