2 Litre Plastic Pop Bottles?
if you want it even cheaper than the carbonator cap (and even more ghetto 
), just go to your local auto parts store and buy some steel tire valve steps, and put an air chuck in your co2 line. if you lose one, it's not dropping $13 every time...
Mr. Beer comes with plastic bottles and they work fine. You can even get new caps for them. They are a bit touchy when it comes to cleaning. do NOT scrub the inside with anything abrasive. just soap and water to clean and then use something like One Step to sanitize. Prime and fill as usual. They had carbonated liquid in them to begin with so they will hold with the beer you put in them. Do NOT use wate bottles! only bottles that had carbonated stuff in them. Hope this helps!
As Car Boy stated, there is no true way to seal a plastic bottle. Besides, unless you want a skunky tasting brew. Plastic bottles DO NOT block light. LIGHT AND OXYGEN are the ENEMY. heineken(YUK) and corona (NO BUENO) are both in a bottle that does not protect the conditioned brew from light. leaving the brew "light struck" which leaves that stinky (sorry dutch fans) smell. (whooo hooo) skunk funs!
it would be much safer too, if you were hiking or anything active. glass is awful when it breaks. a plastic bottle would be better.
I use the carbonator as well, and I can say it works great for transporting beer to a party/brew club meeting. However I would not recommend long term storage with it. You need to recharge it about every 2 days or so because it can't hold a lot of pressure. You can force carbonate with it, but it is a little tricky, and I wouldn't do it except for a small one liter that you shake and keep it connected (it sometimes leaks when you take off the connector if there is too much pressure).
I've used the 2-liter bottles a number of different ways. For brewing, there is a product called Oztops that is essentially a fast acting yeast and a set of pressure caps designed to fit the 2-liter bottles. I brew wine coolers in the bottles, and serve directly from them. The pressure caps relieve the pressure of fermentation, and I wind up with carbonation to boot.
You can also bottle beer in the 2-liters. There is another product called the Carbonator Fill Cap, which is essentially a fitting that screws onto your 2-liter bottle and allows you to carbonate from a CO2 tank.
While plpastics as a rule do breathe, and do allow for oxidation, the PET material that pop bottles are made of is similar to the new plastic carboys on the market. Oxidation is slower, and they are cheap. The main issue is sterilization. Since plastic scratches easier than glass, bacteria can hide from your sanitizer in the scratches. Check the bottles often for scratches and nicks, and let them soak overnight to ensure your best chance at sanitization. And ALWAYS use some sort of airlock. PET bottles can explode under pressure.
Chris
Hay Mon;
Never tried it cut wondered myself if the PET bottles could handle the carbonation??? It would seem so, since the big brewers, ie AB, and Coors, and others are now selling plastic bottle beer. AND, the sode that came in them to start with was also carbonated, thou I don't have a clue just what the atmospheres of CO2 are/were in the bottle when opened....
Give it a go, and let us know how it works.... That's what's great about brewing... always sometin to check up on....
Happy brewin to all and to all a good light!!!
I have used 2 liter, 1 liter, and 20 ounce plastic bottles in the past without any problems. I usually wash them with bleach, and do not scrub, and use the plastic top to screw back on. I have not had any problems, but after awhile, I got enough glass bottles, and 5 liter kegs, that I did not bother with it. I only used them for bottling, not fermenting beer.
There are some soda recipes that have you actually use the 2 liter bottle to ferment the soda in. I have done that before and it worked well.
I would advise not to use empties that had rootbeer in them. We discovered in our home brew meeting that traces of rootbeer flavor get left behind. That goes for your tap lines too.
As for the Carbonator - I have used it often to force carbonate a 2 liter bottle of beer to bring to a home brew meeting. 30 to 35 PSI overnight usually does the trick as long as you shake it until the bottle stays firm. It is a good idea to add more CO2 every few hours too if you are force carbonating as it will absorb.
Personally, I think it would be tough to get the soda smell out of them, it sticks around in the plastic.
I've used the carbonator on 2 liter bottles without any issues. More often though I use 3 liter bottles with the Tap-A-Draft system, basically a system that turns 3 liter or 6 liter bottles into a small kegging system, except the smaller bottles fit in a regular fridge (that is still being used for food...). When I bottle beer in 3 liter bottles I naturally carbonate them and it works great. The nice thing about the bottles is they are really cheap. Just go to the megagrocery store, pick some cheap soda on sale and pour it out. For $5 or so you can get six 3 liter bottles.
It's especially great for traveling, camping, taking beer to a party, etc.
DT