It might be interested to know that there was a study conducted by the fitness guys at Bath Rugby Union which has stated that direct stretching of a muscle in order to warm it up makes very, very little difference to the protection against injury and infact impares the ability of the muscle, as it does not perform to its full potential during the exercise of which the warm up is intended. As such Bath have removed much direct stretching from their warmup routines.
I can't vouch for the integrity of this study, nor can I find a direct source for it. I just remembered reading it when you were talking about stretching. It seemed to go against everything I've ever been told, its results were very interesting, even if I choose to remain a bit sceptical. lol