Staples offers the Acesori 2,600mAh USB Power Bank in seven colors (Sky Blue pictured), model no. A-STK, for $6.99. Plus, Staples Rewards members receive free shipping. (Not a member? It's free to sign up.) That's $53 off list and the lowest price we could find. It features 5-volt/1-amp output, LED indicator, and sleep mode. Deal ends March 3.