Last year Nursery Water offered free reusable bags. This year, they are offering one free bag tag per household.
They go up at 11 CST every day. Today, all 3,000 were gone within 15 minutes! Keep trying though, and you'll get one. (It took me a few weeks of trying to get the bag.) Just be sure to register first, otherwise you'll be on there at the right time and manage to miss out because you have to take the time to sign up!