Replying to Foam pit?

ok so i made a skateboard with old snowboard bindings on it and its really fun to do jumps and stuff like that but when i ride it on the streets i fall a lot because my feet are set in one position and i can not change them after i 180,360 etc. so i would like to build a foam pit to practice doing big jumps 720, mistys, rodeos all that good stuff. it would be like a mini mega ramp, i can make a good jump with ply wood down a hill and make a kicker but the problem is making a foam pit to land in. i do not have much money to spend so i was wondering if anyone on ns has ever made a foam pit or has any ideas my one friend tried to make one before for Roller blading but it did not work he got a shit load of cardboard boxes taped them together and filled it with Styrofoam beads. it broke the first time he hit it. so if any one has any ideas please share.+k