Preserving soda pop carbonation in 2 liter bottles.

How can one preserve the carbonation in those 2-liter pop bottles upon opening? I seem to remember some top-mounted squirt device but can't find it on the web.

Currently, I use my roommate's trick: squeezing the bottle until the utmost amount of air is gone, then tightly capping it. Seems to extend the life a bit, but not much. Anyone have any methods?
We used to drink this Charlie-O stuff. Came with a special bottle and CO2 tank.. you'd put water in the bottle, then the flavor you wanted, then hook the tank up to the CO2 and shake it until it was fizzy as you wanted.

Seriously doubt if you could find one of those systems now.. hmm..

I can't think of a thing that helps! I feel your pain! You could always buy Sam's Cola from WalMart, if you have those around. It's kind of between Pepsi and Coke... and cheaper!
Try a wine store. They have a device to prevent oxidation of opened bottles of wine. Should help with sodas, too.

Must watch dad had told me once about something that helped keep carbonation in 2 liter sodas. Though he couldnt' find such a thing when he went to walmart to look.
DAMN!! You...WIN!

I shall order and try posthaste. Thanks, that is very similar to what I remember seeing!
Soda never lasts long enough around here for that to happen.

If you like Coca Cola though, i've found that even if you leaveit out in a cup, there is still carbonation the next day- get coke if you can afford it, it holds the carbonation better.

maybe keep it in the fridge too?
We don't need no stinkin' gadgets!
Put the cap on tight and store it upside down in the fridge. Seriously, it helps, since the gas can't escape the bottle.
Re: We don't need no stinkin' gadgets!
I can't imagine why upside down would make a difference. If the gas can leak out, wouldn't the soda also leak out with it upside down?
Re: We don't need no stinkin' gadgets!
I wish I could remember where I first read this. But gas rises, and the opening is at the bottom, so the gas stays trapped inside. And I've never had one start leaking on me.
Re: We don't need no stinkin' gadgets!
The gas particles are small enough to escape where the liquid can't. Watertight is not necessarily airtight, in other words. By covering the exit with liquid though, and forcing the air to the bottom of the bottle where there's no exit, you trap the gas in the bottle.
Re: We don't need no stinkin' gadgets!
I was right about to say this when I saw your comment. :P Good call.
I'm no help because I hate soda out of a bottle; I like the taste of metal with my sugar, I guess.

But I had to comment on the ferret icon. <3
Oh, it wasn't that the icon was fantastic (no offense!), it was just that it was a ferret. I've been a 'die hard' ferret lover for years and it's still weird to see them in anything mainstream.