Having just gone through the painful process of making up my final exam (again), I'm inspired to think that there must be a better way. We should have a problem (and solution) repository so professors/instructors can easily find a collection of problems to borrow from or to use as a creative inspiration. It would be nice to be able to say, "I need a dynamic programming problem, a linear programming problem, and an approximation algorithm problem..." and go to one place to start getting ideas. (Right now, all of you that keep your exams online, I'm probably cribbing from you, thanks to Google... I notice more of you are keeping such info password-protected than a few years ago...)
I (obviously) haven't thought much about how this would work in practice, so consider this an open discussion. Of course, there's the problem of keeping such a repository protected from student eyes. Ideally, actually, perhaps we'd have a student site (unprotected) and a faculty site (password-protected). Would you use such a site? Would you contribute problems to it? What sort of incentives would make such a site work? What other uses (besides making up exams and problem sets) could such a site be good for?