The Pocket Power cellphone charger. Wow, 3 hours talk time from one AA battery? Really? Really really? $24.95 with connectors.
Just throw a Pocket Power in your jacket, and you’ll never be stranded by a dead cell phone battery. Using any alkaline, lithium or rechargeable AA, Pocket Power weighs next-to-nothing — thanks to rugged but lightweight aluminum construction. Plugs right into your phone for up to 3 hours of extra talk time! Includes assortment of connectors to fit virtually all popular cell phone models.