Then I found FreeHotKeys. This application is free, not "try-before-you-buy." And best of all, it requires no configuration at all. Just run it. Then, to bring up an application, type option-command + the first letter of the application. Want Mozilla? option-command-M. Want X11? option-command-X. Now, If you are skeptical and saying to yourself, "Gee, that doesn't work for me, I want to be able to change the hotkeys," my advice to you is to try it anyway, because that is exactly the same thing I thought at the beginning. Now I'm addicted to the option-command system.
Get it here: http://batista.org/freehotkeys.html
By the way, you can also assign function keys to AppleScripts and this time it works. Also, this is an application switcher, not launcher. You will have to launch applications manually for yourself---which is fine by me because I usually only do it once per day.
Another note: if your application's windows are minimized (located beside the trash on the Dock) rather than hidden (completely out of view), then no application switcher I've found will bring them to the foreground. As far as I know, FreeHotKeys and others bring up only "Hidden" windows, not "Minimized" ones.

