Most productive conference trip ever

I can confidently say I've never accomplished so much actual work at a conference before. I actually solved a research problem during downtime while at ICFP this week. As a fledgling PhD student I used to take advantage of my boundless free time to think about problems for hours on end, often working into the night. As time goes by I have less and less uninterrupted free time, so I guess that's making me more efficient at using my spare cycles in very short bursts. I guess Butler Lampson would classify that under speculative execution.