The ability to make soda out of plain old tap water still impresses me, but let's face it: the Sodastream contraptions don't match our sleek modern kitchens, do they? These designs, from a German competition, definitely fit the bill.
Over at Germany's Karlsruhe University, students were encouraged to re-imagine the Sodastream in various ways. That bubble-concertina is from Yigeng Meng, whereas the sodawall below is from Soshin Katsumi, which is fairly self-explanatory to anyone who's ever used a wall-mounted bottle-opener. There are a bunch more designs over on DesignBoom's site, but these two are easily my favorite. Just whack a bit of Midori in there, and pass the pineapple juice, and I'm set for the afternoon. [DesignBoom]