1.) I had a student tell me that a biochem homework question -- about why emulsifiers are required to make mayonnaise that doesn't separate out -- actually helped him reason through why a peanut sauce he had made was separated out, and then he solved it by using biochemistry to add a little egg yolk as an emulsifier. Biochemistry is useful! (For peanut sauces at least.)
2.) The same student told me his dad was sitting on a plane next to a medical student from a big state university in the midwest, and they started talking about how his son was taking biochemistry, and the med student mentioned he was listening to some biochem lectures from iTunesU ... and turns out the med student was listening to my lectures! A good reminder that I have no idea what work the iTunesU lectures are doing while I'm otherwise occupied.
Now, I don't think this particular student who told me these stories was angling for a better grade on the final that I'm going to start grading any minute now ... but you gotta admit these are some good stories!