Our second favorite class from when we were in grad school at NYU's Interactive Telecommunications Program was taught by game designer Frank Lantz of area/code. The best project—certainly the most copyright infringing one—to come out of his Big Games class this past semester might just be the Nintendo Amusement Park, "a real life obstacle course which a player jumps through using a power assist harness."
The current set-up is as basic as basic can be: it uses bungee cords, with the player attached to a fixed point on the ceiling. If they manage to get funding, the group behind the project will build a 2-axis ceiling track with a haptic winch, which "would be responsible for determining where the player wanted to go in 3D space and delivering them there safely." Watch the lovingly-crafted commercial (in Japanese, with English subtitles!) on the site to get an idea of what they're trying to do, and how much fun it could be; we're looking forward to trying it out ourselves sometime soon. Hopefully they get their wish and a big company pays them to develop the idea further to make a fun booth for E3 2007.
(Extra bonus item, which some of you may have seen before: our favorite project from 2004's Big Games class (a.k.a. the one we couldn't get into because NYU's registration software screwed us over), was PacManhattan, an urban game that used the streets of Manhattan to recreate the PacMan grid. )