OK.
So, the other night, I was sitting in bed, trying to fall asleep, when I remembered an idea that I had a little while before. I couldn't get it out of my head for at least five or ten minutes, and then eventually fell asleep.
This playertype would have to use extensive scripting; in fact, even though it seems possible to me, it might not be.
You see, the playertype would not be only a playertype, it would use a vehicle, which would be forced or toggled. Probably toggled.
The vehicle would have to allow the player, or force the player to run the running animation, so that it would still walk. It would have no wheels, no model, nothing. This would make it a vehicle rather like the skis.
The similarity to the skis allows more to happen. The player would still be able to run, and run it would, until it reached angles which it could not deal with, in which case it would fall and sustain tripping damage. It would use the jump script from the skateboard, or the abandoned bit of code, jumpforce, would be used. When the player is in midair, and probably on the ground too, the player can tilt and stuff. In midair, it could be magnified to doing flips, barrel rolls, etc. Also, this would probably lend itself to jumping off of and running up walls.
So that's that, and I hope some good scripter looks at this, because I cannot get close to doing this at my level of competence.
If anyone actually starts making this, then please contact me. I would love to test it out.