I saw a fellow at work today with this, and I thought I'd just throw it out there - it's a make your own soda dealeo - obviously, pays out big time over long term (particularly if you drink a lot of soda) but it's a bit pricey (He said around $200) for all the up front costs (including getting the bags of name brand soda syrup.
Sodastream | Turn Water Into Fresh Sparkling Water And Soda