I've always loved soda and can't help but drink a ton of it. After getting cavities from drinking tons of regular flavored soda, I switched to diet. Then I got scared of the asparthame in diet soda causing cancer and many other harmful side effects. So I started drinking simple carbonated water (sprizer). Unfortunately, it only comes in one liter bottles here. So the packaging and transportation costs associated are rediculous. I've found many websites explaining do-it-yourself home cabonation kits that only take minutes to assemble and end up saving so much in the long run. If you can reuse your old bottles of water, then you'll never have to but bottled spritzer again!
I've seen more in-depth instructions that allow you to use a real carbonation motor system so that you have a full soda fountain... but thats more that I need.