CITO was actually the inspiration for a project that some class mates and I did a few weeks ago.
There is/was a cache not too far from my house called "Steed Pond" (GCH1M6), located, conveniently, at Steed's Pond. This place is a popular hangout for kids and families in the summer, a lot of kids from Holt Elementary next door go there after school too. It is quite beautiful, a little patch of "wilderness" in the middle of the Wasatch Front suburbs. The only problem was that that the place was trashed up the wazoo. Styrofoam worm cups, beer bottles, soda bottles, old shoes, and even condoms littered the pond. Luckily I was in a "Small Group and Interpersonal Communication" class and each group had to do a sercive project. Immediately Steed's Pond came to mind.
So a few weeks ago everyone in our group (all 3 of us at this point in the semester) spent 8 hours cleaning the pond to the best of our ability. In the end we filled over 20 full size garbage bags.
Though there was no "Cache In" involved that day, it was definently a "Trash Out."