Windows XP:
C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup
Windows Vista:
C:\Users\USERNAME\AppData\Roaming\AppleComputer\Mo bileSync\Backup
Mac:
/Users/USERNAME/Library/Application Support/MobileSync/Backup
Windows XP:
C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup
Windows Vista:
C:\Users\USERNAME\AppData\Roaming\AppleComputer\Mo bileSync\Backup
Mac:
/Users/USERNAME/Library/Application Support/MobileSync/Backup