haha. this is one of the reasons why i buy used tanks in the first place. i don't have that hold on a shiny new tank. the tanks i buy are usually out of test, so swapping them is easier than waiting for a test to get back, etc.
also, for the poster above, a way that the place can fill it with the tank not being chilled beforehand, is by partially filling the tank, then venting all the gas out. this will chill the tank very rapidly, and then they will do a full fill with the chilled tank. the cost of co2 is pretty cheap, so if they aren't anal about it, they can do this for you.
also, just a caution for those of you getting your tanks filled. i remember a few posts about 6 months or so ago, about someone having their tank overfilled, and when the tank wamed up, the safety disc ruptured, venting all the co2. under normal circumstances, this doesn't pose a threat, just an annoyance at having to go back to the shop to get a new disc put in, and refilled, but this can pose a very severe safety threat (the earlier thread had a small child near the tank when it vented - scary!). if it vents while you are in the car with the windows down, that can also become a very dangerous situation.
this is why swapping is also nice. i know the tank i'm receiving back from a swap has been sitting in outdoor temps for a while, so the fill should be appropriate, and i shouldn't have to worry as much about it.
i guess what i'm getting at, is just remember that all compressed gasses are dangerous, even if they aren't flamable.