Near the end of the year I always liked to through a random "pop quiz" into the mix, only this time it really was a "Pop" Quiz. It drives the students nuts trying to figure out what to study because they don't know what the quiz was on - except that it was a "pop quiz."
I like this because it adds a bit of "pop" culture to US History and the study of pop culture. I have always used this as an extra credit assignment because in most cases the students would have no idea what the answers to these questions are, but they can guess of course. Pair this with photos and videos (YouTube has a lot of jingles and commercials) and it becomes an interesting look back on one of the most "pop"ular drinks in recent history.
There is room to add to this and be creative with your own questions as well. I would not suggest letting the students research the questions, unless you are going to use this as part of a different kind of lesson.