So, I've been using LabMeeting and BibDesk on my Macs. But since I've got a Droid now, I'm still trying to figure out the best way to read all my papers on that device, and probably an iPad when it comes out. Since Flash is not supported, LabMeeting won't work. Obviously, BibDesk is not supported right now. In fact, I'm guessing most of the sites/programs mentioned in this discussion won't work.
So? The only solution I can think of so far to store all my PDF's "in the cloud" is Google Docs or Dropbox. Dropbox might be the winner here, especially since you can get the revision history service. It's not free, but it's cheap enough to be worth it.