My other half is a physio, and as long as I can remember has consistantly maintained that my warm up is abysmal, and my cool down non existant.
I just find the whole thing so... tedious. Yes, I know, I know, I'm a bad boy. But since I don't get pulled muscles and excessive soreness I just figure I must be doing something right. I do a bit of stretching, bit of jumping about for a few minutes, then nip out the gate to disapproving looks from the kitchen window.
(It was interesting to look at my heart rate for the first time though, and see a sharp peak a few minutes after I started the run. Apparantly, this is one of the things a good warm up should avoid.)
I think a big part of the warm up/cool down thing is very dependant on body type. I've always been naturally pretty flexible but I can see if you're not then it would be much more important.
Know what I hate? Needing to be somewhere else quick after my run, diving in the shower and finding that my body just will not cool off because my blood temperature is still too hot. Get out, get dried, realise I'm still sweating. Damn.
Best cool off - a dive into the kids paddling pool in summer. Remember to eject kids first..
(Its nice to see a few other heretics confessing their sins on here!)