[dnanian]

Well...at the same time, it is possible, because it's happening. Your system is constantly active, and making a small change in a big file means that entire big file is re-copied.

Your iTunes library, for example, has multiple parts to it - an XML file and a big database. One change to iTunes (even a play count) means (on my system) more than 400MB of data is different (not counting any content). The same goes for iPhoto and Aperture - smal changes (a photo) mean large data changes (library).

If you're using Parallels or VMWare, the entire virtual disk could have changed just from launching the app. Using Outlook/Entourage? The database is gigantic...

You can certainly look in the log to see what folder most of the time is being spent in, and review the file and folder count that's changing (along with the size). It might help.