Actually, I've been to Walmart lots of times. But I actually went and got a few groceries by bicycle for the first time ever. Back at Christmas, I got a disassembled Arpan Low Gravity bicycle (like this: http://www.arpan.com/english/product.asp?id=9 ). I've had it together for a while now, but finally got the spokes tightened up and tried a useful trip on it. So that's a couple of tablespoons of gasoline that are unburnt.