BTW, my
money's on Tony. 
There you go, we can open up a betting pool on this too. 
 
The best challenge I have seen is what the people who wrote Doom do (sorry
I forget the names etc., but its in one of my Doom books). The challenge of
the sour milk. Basically they let a glass of milk go sour, then the loser
of a deathmatch has to drink it. Motivation is very high. Apparently the
revulsion level of sour milk increases with exposure too.