Igloos are cool. What kid hasn't wanted to build an igloo? You can easily build an milk jug igloo in your classroom with some planning, lots of milk jugs and hot glue. This could be a fun winter craft for the kids when it's too cold to go out.
Rather than just one trash can for everything, this idea would be so much more practical! Fun bright labels, a lovely tray, and a vintage-style litter bin seriously minimize the unsightly stack's utilitarian look.