How can I reduce the time it takes to sync my ipod touch
From everything I've read, photos do seem to be the biggest factor in long sync times. 

Exhibit A: This blog post suggests to not sync photos:


  If I have photos unchecked, everything syncs and it's fast (7 seconds).


You can give that a shot to see if your sync time improves (as a troubleshooting measure)

Exhibit B: Apple Support suggests that importing the camera roll can improve sync times

Worst case, as @hobs mentions, you can restore your device as a new device from a backup (see this Apple Support page for details).