Staples offers the SoundLogic XT 2,600mAh Power Bank Keychain in four colors (Black pictured), model no. SPK26-24/6097, for $8.99. Plus, Staples Rewards members receive free shipping. (Not a member? It's free to sign up. Otherwise, shipping adds $9.95; in-store pickup is also available.) That's the lowest total price we could find by $6. It features a Samsung battery and 1-amp output USB port. Deal expires January 13.