Going to Europe on a school trip in April, and had a brainstorm of how to do this. There are a few micros in very busy sightseeing areas that we wanted to find. There are over 100 students going on the trip, so the plan is to get a group of 10 people or so, and once we've narrowed down the location of the micro, have them pose for your typical touristy group picture. Then I crawl around behind all of them and retrieve the cache!