What do you need to refill 16.5oz propane cylinders at campgrounds?

[New Daddy]

I have a gas stove and gas lantern that both run on propane. Because my family does car camping, we can carry only a couple of cylinders, not a big tank in our car. Is there a way to have these 16.5oz cylinders refilled at campsites? It lookslike campgrounds only have gears to refill bigger tanks, but one of the customer reviews below suggests that there is an adapter that will fit a 16.5oz to a profane refiller. Does anybody know of such adapter?

http://www.homedepot.com/p/Bernzomat...8#BVRRWidgetID