That's cool. Just don't make it be a trivial competition... not like any simple algorithm or something.
I'd personally like to see some crazy DOM scripting (with IE hacks, if wanted) competitions.
Bump DHTML up the next level, and there is enough talent haunting these forums to do that. Of course, one of the things I've been attempting lately is replacing DHTML effects with pure CSS... which is neat in itself.
But yeah, something along a nice piece of coding requiring some complexity, good algorithm(s), and producing a very neat effect is a must.