The ol' iPod (first generation, 5 gig) has been acting up a lot lately: it'll say that it is fully charged, then will go about 10 seconds before the low battery comes up and it shuts down. Finally decided to get a replacement battery from Macsales.com. The battery came with instructions and two small plastic prying tools. Many minutes of hilarity ensued as I tried to get the case open without messing the thing up. Ended up stripping the tip of one of the tools off in my zeal. Here's the trick to getting the iPod open: go into the case right by the Firewire port on the top of the iPod, not near the corner, as the instructions say, and then gently pry away.
The thing's charging right now, so we'll see how it goes this afternoon.