Irregular shaped solids. For example the volume of a candlestick holder. I'm sure there is probably lots of irregular shaped solids used in industrial constructions.
I'd be more eccentric about it just to annoy them:
What does Thanksgiving have to do with volume of revolution? Yea, give them that assignment to chew on over the holidays. Ever been to a turkey shoot? Well, guess it depends if you like guns. Anyway you shoot 12 gauge birdshot at a target from about 50 yards. Closest pellet to the bulls eye wins, say about 20 people at a time (each has a target of course).
Could just leave it there to annoy them further but since it's the holiday and all, may wish to explain how sometimes you need to try many approaches to a real-world problem. Not sure how to solve it and you're just trying things. Sometimes, randomly try this or that to make some little progress, really not knowing which "pellet" you shoot at the problem will hit it's mark. The more pellets you have at your disposal, the greater chance something clicks and the answer falls into place. Volume of revolution is one of those pellets.