I just read, "Messengers of Cool," by Jeremy Caplan, which is about people who seek out the next new trend or the next cool thing. I was thinking that an assignment related to this topic could be to have students work in groups to develop something that they think could be the next fad or trend. Possibly it could be something like necklaces made from twisty ties (from bread bags) or making bracelets from shoelaces. I'm sure the students would come up with much more creative ideas than mine. Students could be encouraged to create a video or advertisement promoting their new item that they think could be a fad.
It could be interesting to see if a group of kids could easily start a trend just by publishing a video to YouTube, somehow illustrating their idea or trend. Could they start a new trend based on a classroom assignment. I think kids would love to find out.