A new service set up by the Natural Resources Defense Council, National Wildlife Federation, and the Ecology Center called Catalog Choice can put a stop to all those unwanted catalogs clogging your mailbox. Since its debut last week, some 20,000 people have signed up for the service, already halting over 50,000 unwanted catalogs. That’s a small fraction of the 19 billion catalogs mailed in the U.S. each year (made out of 53 million trees), but it’s a start. Did we mention it’s free?