According to the Apple website, the batteries last around 400 charges. But I bet the closer you get to 400 charges, the weaker charge you get each time.

I know if you bring them in to the Ipod store they can do it, or you can ship it to Apple. But I bet they charge out the wazoo.

When my Ipod Touch battery starts getting weak, I will just search online and find any alternative I can find instead of paying Apple a mint for a freaking battery.