I played with syncing my photos to my iPod. It is a handy way to have my photos backed up. You can also look at the photos on your iPod which is potentially useful. Unfortunately there is a annoying side effect. Derivative photos get created which are optimized for the iPod. Makes sense since the iPod doesn’t have the processor power to display the full resolution 6 megapixels photos. The annoying part is that it also stores these derivative photos on your mac. My laptop’s hard drive is full. While trying to figure out where all the gigs went, I realized there was a 9 GB (!) folder called “iPod Photo Cache” inside the iPhoto Library directory. My entire iPod library (12,500 photos) is 19 GB. 9 GB of derivative files is a little excessive. Not sure why the derivatives can’t ONLY be stored on the iPod. Must have something to do with speeding up the sync time? What is worse, when you disable photo syncing, the cache directory doesn’t get removed. According to this knowledge base article, you can just delete the directory by hand.