The Ibuildings techPortal has posted the latest episode in their DPC09 session podcast series - a talk from Paul Reinheimer about easy and hard problems.
Consider "Easy" problems in web applications, like login forms. On the surface, terribly simple, slap some escaping functions on a query and you're done! Well, not quite, what about brute force login attempts? Locking accounts? Captachas! This talk will examine a few of those easy problems, how hard they really are, and present specific solutions and methodologies.