http://www.youtube.com/watch?v=NBxj6JqiY_E&feature=related

http://www.steripen.com/content16230

I saw this which is bulky but can be modified, it is a hand crank steripen water purifier called the sidewinder. I like the concept for those cloudy days with no sun for the solar cells and of course no batteries. I like the fact that it will fit on a guyot bottle but you would not be able to see the led indicators plus it's too big and bulky, I'm eying to see if I can modify it and use the circuitry to make it compact.