Des, you said you wanted something humorous for OT posting. Here's one I came up with after Jason asked a question on another list:
How many nicknames, slang, euphamistic terms, etc. are there for the toliet and, if we know, what are their etymological origins?
If I remember correctly, "toilet" is French in origin and originally had to do with fixing yourself up. "Toilet water" in the 18th century meant a type of perfume, I think made from plant extracts (like lavender) and water. You had expressions something like "She made her toilet" which meant she fixed her hair, put on her perfume, washed her face (good women didn't wear much if any makeup in most of the 19th century), etc. I'm guessing at some point, when commodes came inside and merged with a lady's boudoir, you got a toilet room and eventually the commode itself became a toilet. The Victorians especially liked to use French words to speak of things they found embarrassing; well-bred Victorians used the French word for "pregnant" because the English word was considered too indelicate.
I remember watching something on t.v. about this and it's actually named after a man, Crapper, who either invented the indoor flush toilet or made a big improvement to it--I can't remember which. The commodes carried his company logo--Crapper--on them, so they became Crappers (which, when you were the first on your block to have an indoor toilet, you were proud to have a Crapper) and eventually what you put in them became crap.
There is actually still a piece of furniture called a "commode"--it's usually a small chest of drawers that is used in a living room or dining room to hold linens and the like. I'm guessing here, but in the middle ages--and even up until the invention of the indoor flush toilet--rich people had a chamber pot that was set into a piece of cabinetry so they could 1, use it as a seat and 2, fold the cabinet back up when done to hide it's purpose (I've seen some Victorian examples of these on t.v.). I'm betting the word for the cabinet got mingled into its use as a waste receptical and thus you get a commode outside a wooden box.
If I remember this correctly, the term came from the location on board a ship (towards the front) where the "facilities" were located.
Feel free to correct or add, since I'm going on my memories of odd and end bits of information that I have read or heard about and so may be misremembering some parts.