Lego wants to keep its plastic bricks out of the trash. The Danish toymaker is testing a way for customers to ship their unwanted bricks back and get them into the hands of other kids. Customers in the U.S. can print out a mailing label on its site, dump their used Lego bricks in a box and ship them off for free. Lego said the pieces will be cleaned, put in a box and given to Teach for America, a nonprofit that will donate them to classrooms across the United States. If the test is successful, Lego may expand the program beyond the U.S. next year.