I was looking for some new and interesting linguistic phenomena to talk about with my Etymology class, and today I came across snowclones. A snowclone is a formulaic phrase into which we can plug whatever words we want while harnessing some of the force of the original expression. There's a whole database site, but here are a few:
X is the new Y
To boldy X where no man has gone before
To X or not to X
I hope the students will think they're fun (and I hope they'll be able to think of more on their own).