Don't waste perfectly good CO2!! Fill a bunch of 2 liter pop bottles 3/4 full of water, put a bicycle valve into a cap, release the CO2 into the bottle thru the cap/valve via your regulator, shake, and voila, you have carbonated (sparkling) water. I've long been wanting a CO2 cylinder to make my own soda pop.
http://www.instructables.com/id/DIY-...ays-For-Itsel/
http://www.youtube.com/watch?v=lZgyC_av-Ao