I like the idea of "a hacking competition across a couple hours at a SQL Saturday or conference.". As part of performance tuning courses we used to corrupt the students database on the last day. Their final task was to fix the corruption. Another one was to have a poorly performing database with a few tables and stored procs and give participants 30 minutes to do all the tuning that they could. Its all fun, but also interesting to watch how different people approach problems.