I’ve been drinking allot of seltzer recently and started looking at home-brew option on instructables.com
In the process I found a beverage distributor that sells a kit ready to go. Homebrew drops the price from $2 to about 4 cents per 2 liter bottle.
http://stores.kegconnection.com/Detail.bok?no=245
Geer Gas – 20lb CO2 $105, $14 to fill.
829 Ingleside Avenue, Columbus, OH 43215
great article of carbonation – http://www.truetex.com/carbonation.htm