Xlab Aero TT is what I use.

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how about something like this:

http://www.competitivecyclist.com/...FsA&gclsrc=aw.ds

Well if you want to go aero you have a lot of options; Xlab Profile Design and if you want to follow Jan Frodeno you can use the Elite bottle. I have noticed one thing with all of them (tried Xlab, Bontrager and Profile Design). You need to take it out firmly and it always spills some of the liquid (or maybe its just me). I have read that the Elite needs to fully inflated with air or liquid or both. If the bottle isn't completely inflated it can leave the cage.

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"see the world as it is not as you want it to be"