Built a crappy "ski" with a couple of friends for a mountain bike for use on back roads/fresh snow/trails, but it ended up being worse than the regular front wheel (except while going downhill at a decent speed).
These were the best runs. We never made it more than 50 meters or so.
I think I might try a double ski design (so I can't fall over). Has anybody had good luck with any designs? I don't hope to go fast, just to be able to get over more terrain than I normally do without having to get off and walk.