Apple's running an iPod Nano replacement program for first generation Nanos. Apparently their batteries are prone to overheating. I know I bought a nano years ago for Nike+ use, but wasn't sure what generation it was--first or second. Ended up using my iPod touch for the same purposes. Dug up the Nano and plugged it in and found the serial number after it finally had enough energy to boot up. Turns out I do have a first generation one. I must have bought it right when the second-generation ones came out. Looking forward to getting a new one, although I'm not sure what I'll do with it.