How long does it take to charge your itouch?

My friend said it takes sometimes 20- 30 minutes for her's to charge but she also did say that it may take an hour to a few hours for an iPod to charge.

My 4g ipod touch only takes about 10-20 minutes to charge but if it is fully dead i would say probably only 30-45 minutes!!!!!! totaly not 3 hours