For those of you who have osteoarthritis that has made your knees too painful for pill therepy see your orthopedic doc and ask about Halyuronic Acid shots. This is called viscosupplementation therepy and involved a series of injections directly into the affected knee.
The shots are quite painful, but they have extended my ability to ride and delayed the eventual knee replacement surgery that may spell the end of my riding days. When that happens I'll have to graduate down to a side-by-side.
See
http://www.aafp.org/afp/20000801/565.html