Are there any good stretches for the knees? Any thoughts on what contributes to post-run knee pain and how to deal with it?

I'm pretty cognizant of my form while running but I know that I'm not nearly as consistent as I'd like to be. I feel as though I have a pretty straight gait and that I'm not too wobbly while running so I believe my knees are not being asked to do much more than their normal functions. However, at the end of a long run, all I want to do is stretch my knees somehow. When I squat up and down that seems to help, but I don't know that it's actually stretching anything. Going up and down stairs after a long run is a true chore. I have to go slow and hold the handrails. The pain doesn't last long but it sure is uncomfortable. I'm working on a series of running Q&A answers for a blog, www.healthandrunning.com and would appreciate any information or insight you can provide.

Sincerely,

Natalie Friton