The one in Pigeon Forge has been there for a while.  I got to do it about 10 years ago on a trip down there.  It is AMAZING fun... basically an airplane propeller in the bottom of a tube, with a trampoline style screen overtop of it (although the gaps int he material are quite a bit wider to allow the airflow to move more freely)
TONS of fun, 
Definitely a must do again, when I get back down there!
Sol