liquid nitrogen can hover on a thin film of gasous nitrogen if the ground below it is warm enough. I suggest a vehicle that has a large tank of LN that fills four pods with LN. The pods would be open to the ground but not touching it due to liquid nitrogen's hovering effect. The vehicle could be powered by a LN engine (link). It would run entirely on LN, and have no harmful emmisions.-- AlexTheGreat, Apr 24 2006 LN engine http://www.powerlabs.org/engines.htmA simple engine that runs on LN [AlexTheGreat, Apr 24 2006] ...so basically a hovercraft, where evaporating liquid nitrogen raises the vehicle. A fan works better and is cheaper.-- sninctown, Apr 24 2006 liquid nitrogen takes a long time to evaporate when it is hovering. Much longer than you'd think.-- AlexTheGreat, Apr 24 2006 Might make a more compact Zamboni.-- DrCurry, Apr 24 2006 random, halfbakery