My iPod Photo 30GB was stuck in a reboot cycle, and wouldn't take a charge. Before this happened I had noticed the battery life was degrading rapidly, so I decided to try a new battery.
The repair went great. One the new battery was in, the device booted right up. Hardest parts of the repair are getting the case open, and getting the battery released from the adhesive. I did end up disconnecting the data cable to give my self some more room to get the battery pried out. Prying on the battery with a spudger did the trick, but it required quite a bit of force.
The plastic opening tools provided are sufficient provided you don't try to pry with them. Just get them inserted at the top of the device and at a corner, and start working them around the side. That should pop the case open. If you decide to disconnect the data cable, be very careful where you pry. Unless you have seen this kind of connector before, you might be inclined to pry on the female side of the connector and pop it off the main board. Instead, you should gently pry underneath the data cable end.