Solar powered lawn mower. I might like this. In Michigan, I could regularly say, "Oops can't cut the grass today, the sun hasn't been out in a week... lawnmower's dead."
Not solar powered, but green just the same. I think this is an example of an invention that cuts off its nose to spite its face.
This is the one item that I think has real potential. It is a cell phone charm. It is solar powered and you use it to charge your phone. I think that could be handy.
Happy Earth Day,