The other day I bought a solar converter backpack ( [Link]
) and I'm pretty impressed with it so far. It's feels like a quality product. It's tough, somewhat water-proof, and the solar panels charge the battery in about 6-10 hours (depending on the strength of the sunlight). I'm inspired now to see if I can use only solar energy to recharge my PSP and DSi, and other gaming products (maybe my iPhone when I don't need to sync it). I wonder if it would affect my electric bill at all, but that's beside the point. I could become completely mobile in my gaming. I wouldn't need an outlet to plug into, just the sun. I could go ANYWHERE and still be able to turn on the PSP/DSi for a few minutes of fun.
The possibilities are endless. If there is an earthquake I will have something to charge all electronics, if I go to a foreign country I won't need to worry about converters and voltage . . . it kills a lot of birds with one stone!
If you're interested in the backpack, I definitely suggest checking out the website and seeing reviews for it on places like CNET and around the net.