I think Google Gears handles the update from offline to server also…
I had another flash (when you get tired of them, just tell me :P) in regards to the “Stay logged on” feature.
What I’ve noticed is that if I put my computer to sleep and then come back to it later with my browser still open, I can still view what’s on my calendar for the current month, try to add or edit items, but if I try to actually make a change it gives me a “Session Expired” error, I click OK, and i can still see the calendar and everything.
My suggestion would be:
If the system detects the session is expired, it shows you a box that says “Session expired, please re-enter your password: [********] [OK]”, and will have kept in memory the change you were doing. It logs you right back in, does the change you requested, and voilà! You don’t actually need to remember sessions and logons, you just have people re-enter their password (which isn’t very annoying or intrusive if you ask me).