If your iPod battery is crapping out on you (like mine is right now), there are several online sources which sell replacement batteries for a very reasonable price. I think I'm going to try this one out pretty soon for my third gen iPod:
http://eshop.macsales.com/Catalog_It...em=NWTIPOD8503
And the review:
http://ipodlounge.com/index.php/revi...atteries-ipod/