[dnanian]

In general, we suggest you quit as many programs as you can. But, for the most part, applications don't leave their files "open" under OSX.

There are exceptions: for example, Microsoft Entourage leaves its large database open, so I always suggest quitting that. But, otherwise, there's little trouble backing up "open" things, because they're often not "really" open, or -- rather -- being written.

(If there is a problem, though, we'll issue an error.)

Hope that helps!