I just got back from the MicroCenter computer store and saw something there that I thought might be of interest to those who don't keg and don't have a large CO2 bottle, but would like a little CO2 for filling the carboy or bottling bucket headspace after racking to protect against oxygenation. It's sold for dusting electronics - product name is CleanDRx - CO2 Air Duster. It's a hand held case with a trigger - insert a 16 gram CO2 cartridge into the unit and press the trigger to squirt CO2. It says on the package "oil-free" and comes with 2 16 gram CO2 cartridges for $13.99. No idea how many carboy/bottling bucket top-offs you could do with that, but might be worth a try for someone who only needs it occasionally and doesn't want to invest in a 5 lb. or larger CO2 bottle. I didn't get one because I have a keg kit coming next week from KegConnection. but would have liked to have had something like that in the past.