At KinToki-Con I ran an event called "Crossover Mania." It was simple – over time people picked an anime (though any media was allowed – this was an anime con), and figured out how to tie it to another anime. As we went on we wrote down the media properties on paper and diagrammed how they connected – a lot of tape and arrows was involved. Eventually we had an incredibly silly, yet strangely coherent crossover.
How crazy? Well it mixed Space Pirate Harlock accidentally creating the time/space warp Bermuda Triangle while under mind control of the villain in Code Geas. And THAT wasn't even the core plot, that just got the initial crossover to happen (mostly involving One Piece).
Now this was a deliberately silly exercise, but the creativity that started flowing was amazing. Best of all no alchohol was invovled, at least on my part. It was insane, it was crazy – but it was also imaginative and it made people's minds work.