I was riding my bike through Venice last week and I came across this oddity. It's a custom bicycle that looks like it was designed to ride on the sand. Each rim was actually had 2 bike rims and 2 hubs. The wheels looked like some innertubes that had some sort of tape on it for traction. I couldn't find the owner anywhere around but I would've loved to have taken it for a ride on the sand.
This isn't the first time that this kind of thing has been done. Hanebrink has made an all-terrain bike (pictured below). I've seen a couple Hanebrinks around Venice and Santa Monica and they seem to work really well going over even the softest of sand. I'd love one if I could afford the hefty $3,500 price tag!