Your biggest non-technical hack/discovery
Shooter: I made all of the public area lights at a major hotel and convention center strobe for about an hour during an international science fair.  The hotel had a huge glass atrium with elevators and several thousand bulbs, so it was quite a spectacle.   It looked like a single huge strobe light had landed in the city center.It made the news, and I won our (informal) pranks contest for that year. I felt it mostly made up for my loss the previous year (the shaving cream dipped in liquid nitrogen and then packed into a competitor's car was a poor showing, prank-wise.  It was unoriginal, it ruined the upholstery of the poor car, and it wasn't as dramatic of an effect as one would think for the trouble.  Too much of the shaving cream never expanded after can removal and thawing.)