I had this idea as an overlay for DL's now defunct People Mover (WDW's TTA), but it could be built from scratch if need be...
Make essentially a grown-up verison of the Buzz ride - a sort of large-scale laser tag or target shooting game on a moving track. The vehicles could shoot at targets mounted on top of the buildings around Tomorrowland and in the dark rides it passes through, or even at eachother if it was safe to do so (lasers, eyes, might be trouble).
For improved repeatability, the targets could be moved around once in a while, or completely hidden unless you already know where to look. Targets could be scored based on their size, distance from the shooter, and maybe additional points for moving/swinging targets.
I also think they could use the readily available technology used in Fastpass so that people could use their passports as registration cards and keep a running score during their stay (or over a longer period of time for AP'ers). Like on an arcade game, there could be a tally board near the ride's queue entrance monitoring the highest scoring participants - everyone could even come up with unique (albeit P.C.) handles/codenames, similar to the ones used on these boards. There could even be annual tournaments, maybe with awards and stuff...
Just an idea.