I found this on amazon a couple of days ago, the only reason I haven't bought it already is I cant figure out the correct diameter or whatever it is for the jack. I'm gonna go to a best buy or radio shack for assistance on this.
http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=USB to DC 5v
http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=USB to DC 5v