Sometimes the simplest of tools can be overlooked. In the ed tech world, it is easy to get excited about the amazingly powerful new whatsit, neglecting simple, culturally relevant, and socially leveraged tools like memes and SMS strings. (We both know your time online is punctuated with at least an occasional few mindless minutes full of “Y U No…” and “The 48 Funniest Autocorrects of 2013” threads. Your secret is safe with me.)
Memes and SMS screenshots are both prime examples of summary, with which most students are already very familiar. One word of caution, though: Memes are a repository for a lot of different ideas, including those ranging from generally untoward to downright repugnant. You may be better off downloading the blank images and providing them to students with a direction to use their favorite generic image editor (like GIMP!) and the awesome power of Impact.
I will let you Google meme generators for yourself, to absolve myself of the culpability of links, but a great SMS spoofer I am not afraid to link to is iFakeText.