The Sun Jar. This is perfect for that greener than green friend of yours, as well as your nerdy Science lovers.  Made out of a traditional Mason Jar like my Grandmother used to can pickles in, you set this light out to charge during the day, and get up to 5 hours of light on one charge!  This is the coolest thing I have seen in a long time.  Great gift for kids too!

Go HERE to buy (it's CHEAP!), and click below for illustrations.