It's Outdoor Month, so why not take your gadgets outside with you? What, no power you say? Problem solved.
Brando's Universal Solar Charger allows you to charge most cell phones and any USB-device, just as long as its recharging voltage is 4.5 V. If you're on the go, and it's not a particularly sunny day, you can charge it up beforehand with a standard AC adapter.
Available here for $69.