What if you added a few new fields to the messages--- one for a due date and one for the price-- then allowed people to sort threads based on their due dates, prices, post dates.. etc..
As a newbie here I can only post in contests that are $50 or less. So I'm browsing through on my slow connection (which will be upgraded here in a few days, YAY!) trying to find contests I can enter and I'm never sure when they're ending. It'd be super cool if we could search for things that are under 50 and still running, or under fifty and already over.. or even over 200 and already ended (to see what kind of work is done here) or whatever.
Anyway its just an idea. I couldn't do it myself, but I do know it's totally possible and wouldn't be terribly hard to implement.