How about something similar to the POTM contest? Basically,
the creator gives a fiendishly difficult problem to solve, and then
all the solutions "compete" against each other in number or results,
speed, and code size. (The latter two are used in case of a
tie). For example, I recall one contest was where you had to write a
program that would come up with as many legal words as possible,
when it was fed in a 10x10 grid of letters, by going from
letter to letter (and no backtracking). There were some other guidelines/clarifications
as well, no need to go into them here. Then the program that
output the most number of valid words (with a 10 minute time cap)
won, and if a tie, the shortest code did. Let me dig out the URL
for the POTM....
http://members.tripod.com/~POTM/
(I like the perl golf thing too. The Mad Libs was a fun problem
to solve.)