The £5 Challenge
This challenge involves splitting your group into teams and giving them each a fiver and a list of criteria for what they can do with the fiver.
This could include things like:
Find the strangest object you can
Buy something you can wear
Buy something that will feed more than 2 people
Find the cheapest thing you possibly can (receipt needed)
It works best if you add things yourself that fits your town/village/city!