Never used. Have two and selling one. Apple sells it for $29 + tax.

Overview
Featuring a new, ultracompact design, this power adapter offers fast, efficient charging at home, in the office, or on the go. It works with any iPhone and all iPod models with a dock connector.
http://store.apple.com/us/product/MB352LL/B?fnode=MTY1NDA0MQ&mco=MTM3NTI0OTI#overview