Heres one for ya :P
Bluejinjo showed me this one, and in my opinion, its really cool :D.
Ok, goto map map90, ok? ok.
You gotta have 2 people for this one. if you dont, just do splitscreen.
Have somebody be tails and somebody sonic. Have them both be at the highest spot on the level.
Then, have tails fly and sonic grab on. after a while, you will see that, for some odd reason, tails will be walking on what appears to be an invisible floor, sonic still holding on. Now, if sonic jumps off, tails will jump off too.
Screenshot coming, just hold on...
EDIT: damn it, cant seem to recreate it.