I noticed that this show, "Supernatural" has been mentioned in this thread already three or four times, so I apologize for the overlap.
However, I happened across an episode guide to the show "Supernatural" when I was looking for historic references to the string "The Song Remains the Same" which I'd heard an announcer mention about a poker player's luck remaining bad, he said something like 'poor Charlie, for him it seems the song remains the same, he's just had no luck' or something to that effect. There may be other things that I missed in that episode guide since I can't say that I know everything that Plant or Jones has done post LZ, but if anyone's interested to see if there are some blanks to fill in, the guide is at http://www.tv.com/shows/supernatural/episodes/
It's pretty interesting to give it a once over if you have a couple of minutes since there are other bands' songs, movie titles, pop-culture related things named as episodes in that show that most LZ fans will recognize.
20060928 Season 2 Episode 1 -- In My Time of Dying (First episode of season 2)
20070201 Season 2 Episode 13 -- Houses of the Holy (Last episode of season 2)
20070503 Season 2 Episode 20 -- What Is and What Should Never Be
20090507 Season 4 Episode 21 -- When The Levee Breaks
20090514 Season 4 Episode 22 -- Lucifer Rising (Last episode of season 4)
20100204 Season 5 Episode 13 -- The Song Remains the Same
20100422 Season 5 Episode 19 -- Hammer of The Gods
20100513 Season 5 Episode 22 -- Swan Song (Last episode of season 5)
The show continues to this day, it is in its' ninth season, but I did not notice any more LZ related stuff since season five.
I love this thread!