What I have:
X Terminal
Gaim
GPE PIM Suite
A couple of episodes of The Simpsons

What I've tried:
Abiword: Didn't work. Couldn't open a single document properly.
Slimserver: Had a great time streaming music to the 770, and controlling the music playing on my other computers. I'm still trying to stream music from outside my network, though. Haven't had much luck with that.
Patiotunes: A web remote control for iTunes, works great on the 770.

What I want to try:
Thoughtfix's USB host methods.
VNC.

What I'd like to see:
Kismet, or some other network sniffer. With the range this thing has, it's just begging to be taken for a wardrive.