I was at the Hotter 'n Hell 2008 this past weekend and saw a booth for BottleSox. Apparently this is a "koozie" that covers the entire bottle that keeps it completely insulated and made from the same neoprene skin diving suits are made of, AND fits in most bike bottle cages. I almost got one but I wasn't riding due to a sprained ankle so I didn't indulge. Anyone out there ever heard of these and do they really work? I got a card and they are at www.nichelab.com if you want to take a look...anyone who has used one I would appreciate your opinion of them. The booth was making good sales but I would like anyone's opinion before I order any. Thanks!

Cute.

But I prefer function, so at least they fit in the bike's cages, like THIS.

I used to cut the tops off of old tube socks to wrap my water bottles. The idea was that a wet sock would keep the water bottle cool by evaporation. I never thought it worked very well because the sock dried even faster than ice melts in an ordinary uninsulated water bottle.

I pretty much just drink warm water today.

They actually had a 20 oz. and 24 oz. (I use 24 oz.) Polar bottle there actually using a BottleSox over it and said it worked even better...sounds like I need to just order one and test out for myself!

Performance bike used to sell something similar in the late '80's early '90's

I've been disappointed both in the neoprene socks and in Polar bottles. REI had Polar bottles on a clearance table last year and I bought two of them. After they didn't seem to work very well, I put a regular bottle, one with a sock and a Polar out in the sun for an hour, then stuck a thermometer in them. They started at 55 degrees (temp out of the tap from our well). and there was only 5 degrees difference top to bottom at the end of the time. It was detectable when I drank, but nowhere near enough to make me say, "Ahhh."
They both do keep water from freezing quickly in winter, but if it gets that cold, I usually don't ride long enough for that to happen anyway.

The effectiveness of that should depend on how dry the air is. In Grand Junction, it probably works great. In Houston, not so hot. Similar to using a swamp cooler.

BTW, the "wet bulb" temperature should be more or less what the bottle gets cooled to, and you should be able to look that up as a function of temperature and relative humidity.

Your expectation is too high. For what yer looking for, must spend like 10x, if such space-age thin but super-insulator is available.

Of course! more insulation the better. Buy two socks one bigger size than the other, then "double" bottle it.