There was an episode of "Dharma and Greg" with a Joni mention, but since it wasn't central to the plot (and I forgot what the episode was about) it would take luck or a DVD set to find it, unless someone else here remembers it. I think it was Greg's mom who had a new hairdo, and her husband (?) exclaims, "She looks just like Joni Mitchell!" I have a VHS of this somewhere...I'll try to find it.

(Contributed by Gary Z. )