http://www.homedraught.com/
You'll have to put up with 10 pints of Grolsch/Carling or Coors Light, but the bottle and tap system are fully reusable with a little bit of force and modification. Excellent for parties, festivals, making sweet sparkling cider etc.
After posting in the iBrew thread, I have decided to make a simple user guide to show how easy these are to re-use.
Once you have got your hands on 1 you will need to make a few small modifications to make it easier to keep re-using.
First you need to get the co2 bulb holder off. These can be hard to remove because they lock in place with a rachet system and you have to snap the rachet tabs to be able to unscrew it.
If you cant do it by hand, gently grip the bulb holder with a pair of pipe grips.
Once the tabs are snapped off, clean up the edges of the plastic with a file or some sandpaper.
You might find removing the co2 bulb hard work, so put the end of a big bolt in the hole at the bottom of the holder, and push against a hard surface.
Replacement co2 bulbs are a tight fit due to the 3 'ridges' inside the bulb holder, so remove them by sanding them off.
I wrapped sandpaper around a big allen key so I could sand all the way down to the bottom to fully remove the ridges.
Once sanded, your bulbs will fit in nicely.
Now all you need to do is sanitise everything, fill it with beer/cider/wine charge it with co2 and put it in the fridge for a couple of days.
The replacement bulbs are slightly longer than the original ones, so as soon as you hear it inject, stop screwing them otherwise the co2 freezes the plastic and makes it very brittle.
Cheapest place I have found new 16gm bulbs is here
Sounds like there's a story there.