Just some I can think of now:

1. MicroB
2. xterminal with root access
3. DRNOKSNES with Wiicontrol
4. Flashlight
5. mplayer + SiB with non-transcoded xvids. (with keyboard controls!)
6. FM Transmitter (Simple FMTX widget)
7. openSSH and sftp into it via wifi then transfer an MP3 and play it.
8. Just switch between apps using task switcher.