ORIGINAL: countryboy17
If there is a tractor suppy store near you then your in luck. The next time they bring in a load of trailers go to the store and ask or take the foam blocks that the trailers are stacked on. They stop the arrow fast and then you have 6 sides to shoot at and it FREE and you can make a wallof them or just take one there real light. If you ask to have a block of foam just make up some good reason like your kids school project or else they might start selling them as blocks.
countryboy, you're from Boca Raton, I work in Boca. I don't know of any tractor supplies around here though.