As you'll know from my Dry Aging Beef post, I am the proud owner of a Summit Full Keg Beer Dispenser (5 lbs. CO2 Tank Included):
When you have a keg in the kegerator, a CO2 bottle is needed to keep the beer charged.
You will have a CO2 5lb tank, a gauge and a tube with connectors each end.
There are two types of connector for charging a beer keg, one for Domestic and one for European styles. You have to switch out when changing between the two, but it's not hard.
And it's just as easy to switch the connector to the Carbonator Cap.
You can make your own, shown here, or you can buy them here.
The latter are pretty pricey, but I will show you a way to rotate them effectively, yet still have several bottles of carbonated drinks with only two caps.
Here are the ingredients and machinery you need to make club soda.
You will need to collect a few PET bottles. These are easy to find - any carbonated soft drink in plastic is in a PET bottle. PET stands for polyethylene terephthalate, it's the same stuff they make polyester suits out of.
Once the contents are consumed, you can re-use these bottles dozens of times for your own home carbonation.
Here is the trick to get lots of carbonated bottles with only two carbonator caps:
use your freezer. Once you have a pair of plastic PET bottles carbonated, freeze them for 1-1/2 to 2 days.
The carbon dioxide will be fixed in the frozen liquid, and you can swap out the expensive carbonator caps for regular caps, and let them come back up to temperature in the refrigerator.
When I first tried this, I used orange juice, but only froze them for less than a day. The frozen froth that came out was a truly intense frozen orange dessert.
You might also want to try carbonated chicken consomme. I like to call it "chicken-up"