I don't buy the argument that people need to drink eight glasses of water every day, or that they should start drinking before they feel thirsty in order to avoid getting dehydrated. Why not behave like other animals and drink when you are thirsty?
That said, just thinking about club soda makes me thirsty. I don't know why, but fizzy water is very satisfying to me, and much tastier than flat water. I'm usually too lazy to stock up on bottles of club soda so I don't drink it that often. But a couple of weeks ago my family bought me a water carbonation system for Father's Day. It's called the Sodastream Genesis and it costs about $(removed) It comes with a CO2 cartridge that makes about 60 liters of soda (I have a feeling I will get more liters than that, because I like my water lightly carbonated).
You can return the empty cartridges to a participating retail store and receive a full cartridge for about $(removed)
The appliance itself doesn't use batteries or electricity. You just screw in a plastic bottle and press a button to release the CO2 into the bottle. It takes about 5 or 6 seconds to carbonate.
This has turned out to be one of the best Father's Day presents I've ever received. I've got it right next to my beloved espresso maker.