SodaStream is cool and all but I've found Sparkel to be better
Basically the same thing but you provide the Citrix acid and baking soda to make the carbonation right in the machine so it's wayyyyyyy cheaper to run.
Also doesn't void warranty to use alcohol in it, shits great for everything from recarbonsting flat soda to giving alcoholic mixed drinks some fizz
Someone on Amazon reviews even carbonated their milk like a madman