Watson Adventures Scavenger Hunts

This is pretty cool. I've actually thought over the last year or so that it would be fun to do a large scale scavenger hunt. I haven't done one since college, which was also very fun. The ones organized on the above site is answering questions, and not finding items.

I wonder if anyone has arranged hunts where the teams aren't local to eachother. Two (or more) cross state/country teams which have to get certain items, and photos. The team to get the most in a certain amount of time wins. I think it's doable.