Ask Slashdot: What Makes a Great Hackathon?

beaverdownunder writes "I recently attended a 'hackathon' that was really just another pitching contest, and out of frustration am tempted to organize an event myself that is better suited to developers and far less entrepreneur-centric than some of the latest offerings. What I'd like to know from the /. community is, what would you like to see in a hackathon? What are some good hackathons you've attended that weren't just thinly-veiled pitch-development workshops? I have an idea around assigning attendees to quasi-random teams based on their skill sets, then giving them 48 hours to complete a serious coding / engineering challenge (probably in the not-for-profit space) — but maybe you've got some better ideas?"