Kind of cool old-school snowmobile / tractor thingy:
Via Make
If you get bored, since it is a little slow paced, at least skip ahead to abut 7:25 to see the corkscrew things mounted under a car. Somehow I imagine modern cars are a little less hacker friendly. Also, at 9:20 or so, it shows it can run on dirt as well.
After watching that, I started to wonder why I’ve never seen anything like before. It seems like it would be perfect for military use. So, I looked around a bit and, low and behold, the Russians tried it out:
And, at least one modern company, Tyco, has picked up the technology (their version also goes on water):
Three pretty distinct takes on the same technology.
I eventually found a wikipedia article on the concept, and it sounds like the concept has been toyed with for a long time, but it’s not very good/fast on plain old dry land, so it doesn’t get used a lot.