Just got word of an interesting new program that is going to launch soon at Wal-Mart stores in about 30 states. A paintball tank exchange program. I think it's a neat idea. Lots of folks who play paintball don't live close enough to a paintball shop that can fill tanks but chances are there's a Wal-Mart nearby that they probably already shop at anyway. 9 and 20oz tanks will be available, you just exchange your empties for full tanks in sporting goods and pay the cost of the co2. The program is being handled by the same company that already does the propane tank exchanges for Wal-Mart.