Where SodaStream has decided to abandon the whole "environmentally friendly" aspect of their business, Gaia Soda steps in.
Essentially the same product as the SodaStream, Gaia allows you to make your own sodas at home. The difference is in the syrup, which is supposedly organic and all natural, and the CO2 tank, which can be re-filled anywhere instead of requiring the owner to mail it off.
As it's very environmentally un-friendly to re-purchase something you already own, Gaia is selling an adaptor so you can get your SodaStream CO2 tanks anywhere. Of course the syrup will also work with your old device.
It wouldn't be completely "hip" without a Kickstarter, and that should be arriving soon according to Gaia.