Well sir ... I was one of those who started such a thread.
The basic answer I got back was that people seemed to discover two primary uses for the palm.
One is an auto dice roller that would be spreadsheet based, although folks I had talked to said that they had some trouble finding one ... maybe Docs to Go v.8 can do it? I only have v.7 on mine and have not tried.
The other use for it was viewing .pdf files - now I have not tried to do this yet, but there is a prog called PalmPDF out there that is supposed to be the best sort of thing for .pdf files. Even so there would have to be a lot of scrolling left to right and up and down. I think it would be a pain in the neck.
On a separate level, though, I think the palm could be used for simple docs of info, etc. that could be turned into .txt or .doc files and kept on the side. Probably would be of more use for the DM I guess, rather than the player. If you got a Palm keyboard such a thing could be helpful even more, I think.
But from what I know (not much admittedly) if folks like keeping their rpg stuff in comp form they usually just keep it on a laptop that they lug around with them.
Personally I still like the old paper, pencil and dice (with proper bag) image, but things and taste can change, of course!