There is nothing finer than trekking to base camp, roasting marshmallows around a campfire and climbing into the tent to snuggle inside the sleeping bag and watch Team America World Police on my PSP. Trouble is, the batteries run out after the first night. At least that was the case before I discovered
this Solar Charger from Brando. It's got a built in 1800mAh Li-Ion battery and recharges the PSP in 4 hours, even if it's cloudy. It even works in artificial light (no more will you waste batteries reading books with your flashlight). Can be used with Sony PSP, Nintendo DS and GBA-SP. Retails for $35.
Solar Charger for Portable Game Consoles [Portable Gadgets]