The receiver of the wedgie, would by laying on he ground, preferably face down, with they're underpants securely fastened to some strong cord, at each hip. The cord, would be then tied to the pegs of a BMX bicycle ( if you wished to extreme it up a little you could use a motorised scooter of some sort :P ).
The rider of the bike, would have enough slack on the cord to ride up from behind the person on the ground, giving them enough time to introduce the skit; "Hello im *blank* and this is the wedgie of mass destruction!".
By the time thats been said, the bike rider would of gone past the person on the floor with enough momentum, to properly yank the cord and give someone one HELL of an alternative wedgie :)