Why don't you want to stretch out of the pool? Some stretches are best performed with your head low, or sitting down, so they would be impossible in a pool!
I think this is the link Nancy meant to paste: www.sparkpeople.com/resource/fitness_artic
Any stretches can be performed in the pool. Just remember to stretch the muscles you've used, which in swimming is pretty much all of them! :)
Aim for shoulders, neck/back, abdominal obliques, quads, calves and hams at the very least.