Thanks for the encouragement, the doctors don't seem too worried either. I've just never had any nagging injury before in spite of a life time of depending on physical work to make money.
I read all those studies- at least when they reach the NY Times health section and I was aware that runners don't have more knee problems than folks who ride bikes or do other things that would seem to be less wearing on the knees.
While I've stopped running I've started stretching and doing heavy calisthenics like push ups, pull ups, etc. If I can't outrun them I better be prepared to make my stand.