I turned on fast user switching (which I am very excited about). Just after switching to the login screen, without thinking, I hit the Hot Sync button on my Palm Pilot stand. To my surprise, it synced to the logged-in account in the background. Also while logged in as another user, it worked to the background account to which the Palm Pilot belonged. Pretty nifty!
[robg adds: The general intent of fast user switching is that background processes keep running, though that statement has its limits (iTunes stops, iChat disconnects, etc.). I'm running this hint as a general reminder that you can do such things ... but I'm not planning on running a hint for every process that keeps working in fast user switching mode!]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20031027185802974