Kirsten's Fourth of July Fun is now retired, but you can make your own using a few supplies from the craft store. I just drew the design onto the side of the crate using a black Sharpie. You can print out a 31-Star flag and attach it onto a wooden dowel.
You'll need a small crate, one with a handle or attach your own. I printed off the White handbill with Independence Day activities printed on the black.