http://www.apple.com/uk/support/ipodnano_replacement/
If you have a 1st generation Nano, it's going to explode and burn your house down* so check if you're eligible to have it replaced.
Not sure what they'll replace it with, but worth a punt. You'll need the serial number (and a magnifying glass to read it) and your Apple ID. Takes 2 mins.
*possibly



