I've now taken a couple of evenings off, and the knee is feeling much better. The pain is totally gone. I did do some walking yesterday and today during my lunch hour, about 1.5 miles each time. Yesterday I could feel a twinge of pain/tightness, but today was completely pain-free. So my plan is to go out for about a 3mi easy run tonight and see how it goes.
On another note, last weekend my wife ran her second ever 5k. The kids and I were there to cheer her on. As she rounded the final corner, my oldest daughter jumped in and ran the last 50 yards or so with her. It was really cool. And as an added bonus, apparently a race photographer captured the moment: