DK-Prof--
Chondroitin and Glucosamine are GREAT. Check this link [url]www.drtheo.com[/url] for more specific info about the daily recommended dosages and potency testing (too many supplements have nowhere near the amount of glucosamine and chondroitin that their labels claim) of the various supplements.
I was a catcher all through little league and high school baseball, so I have my share of wear and tear on my knees. That said, when I read "The Arthritis Cure" and started taking the supplements, I noticed a HUGE improvement in my joint health.
BTW in order to see positive results, you need to be taking something on the order of 1600mg chondroitin/day and 2000mg glucosamine/day. Also, it will take 6 weeks of taking this amount daily before you rally notice an effect.
It's worked wonders for me, but as always, I'm not a doctor but I play one on TV, and YMMV.