I've had some great ones over the years, highlights for larger teams include:
- Sailing out of Portsmouth (generally went horribly sideways but in very entertaining ways - one boat broke its mast and nearly ran into HMS Daring, a new starter threw up over the CEO and someone got knocked overboard)
- Team sports day - trampoline volleyball is very funny.
- Go Karting - a load of over competitive sales people getting beaten by pre-sales was entertaining.
- High Ropes course - go ape or the like, again the mix of people made it very entertaining.
- Segway rally - basically a load of daft games and 'off-road' racing on segways
- City Adventure - you split in teams and wander around a city answering questions on an iPad - actually worked pretty well (partly due to the high rate of pub based questions)
- Octoberfest - this is a very bad idea and i wouldn't recommend it at all, great fun though
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- Great British beer festival - similar to last point - good for introducing colleges to your local ales
- raft building - again sounds awful but the open bar helped, as did the hot weather
i'm going to be planning one soon and thinking of doing the axe throwing thing in London