Stretching is silly, especially cold muscles. All you really need is to get on the treadmill for 5 minutes before you workout to warm the muscles up.
I also do a substantial amount of running and there is a very brief stretching routine only AFTER running at a slow pace for half mile to two miles. And I don't stretch at all for lifting because the impact on my leg muscles for a long run is not at all like the impact on your arms for a brief lifting session.
If you think about it, strength training is, in itself, stretching.
Besides, those guys I see stretching at the gym always look like complete pussies.