Attached is one of my favourite cartoons involving lava lamps. :D Found it via Google.
There are other media references...
-- In the Sopranos, Adriana La Cerva runs a lamp in her home.
-- In the British TV show, "Keeping Up Appearances," the "oakie" house has a lamp running in the background.
I know there are more I have seen but my memory is deserting me. Of course, you could always stay up late for the "Flower Power" music collection from Time Life Warner or whatever... about four lamps on that one!
Does anyone remember David Byrne (Ex-talking Heads) on Top of the Pops (Uk pop music show) singing a tune called 'Lazy', circa 2002 and flanked on stage by two magnificent Mathmos Lunars? (Red and Green wax respectively I think). A Mathmos Fibre space was also trying to muscle in on procedings Lol.
It was a great performance as you would expect from a great showman like Mr Byrne, made all the better by the decorative input of the Mathmos beauties.
George and Mildred (UK Sitcom from the 70's) used to feature a Hunter Lamp which was always running much to the consternation of Mildred's snooty sister.
I know it isn't a cartoon, but my absolute favorite movie clip is from Mo' Money in 1992 with the Wayans brothers....they are in a club dancing and behind the bar is a wall full of what could be close to a hundred lava lamps all lined up in rows and columns, they are all running so beautifully....an inspiration for my "wall of lava" one day!
I can't find any clips of it online, I will have to upload one day if I can get my hands on it!
I have had Lava Lounge (22"x17.5") hanging on my wall since summer 2006; I believe it is still in stock. Most of his art is centered around olives and martinis, but I posted these since they feature Lava Lamps!