I need some free moving boxes?

I live in a fairly small town. The only grocery store is Wal-Mart. I wouldn't have a problem getting boxes there, it's just that they keep telling me to come back at, like, 11pm-2am to pick up boxes from their nightly shipments.. Well, I just don't have the time/energy to stay up that late and get them. Is there any other way/place I could get boxes?