This looks like a very worthwhile project, and would be a good way to get acquainted with others interested in geocaching.
News from the Geocashing web site
Every April, geocachers around the world get together and clean up their local parks. It's just one way we can contribute to the maintenance of our outdoor spaces and to say "thanks" to the land managers that help to make our parks a great place for geocaching. Learn about how you can start your own CITO event, or just how you and your family can CITO every time you go geocaching.
This year, Trimble has partnered with Groundspeak to help sponsor Cache In Trash Out Day. As a result we can again offer the CITO t-shirts at a deep discount of $4 for geocachers to proudly wear at their event. Happy geocaching and Cache In Trash Out!
To read more go to the Geocashing Web site.