As silly as they may be, if a teacher incorporates a meme into a lecture or powerpoint presentation, I feel that it would greatly return attention to the presentation as the children would want to find the "Easter Egg" that is there for them. While I'm sure that not everyone has heard of a meme before, there is an entire site dedicated to the production and sharing of them which you can find here, but I suggest you look through whatever it is you may find interesting in order to understand exactly how they are supposed to work. While I know it is incredibly informal and it is relatively risky in terms of introducing something that children go wild over, I feel that the familiarity of these would greatly help with student attention spans.
Using them on a variable interval, say having one at the beginning and end one day, one just in the middle the next, one at the end after that, etc. so that they will never know where it is, allowing for them to potentially keep watching in order to be able to enjoy it. Also, I think that children learn much better through association with things that they already know. If they can relate to having seen a Paranoid Parrot meme, and the teacher can insert something like a current healthcare issue or a current craze in society with a sociology class, then I think they will be able to recall it better.
This is just me, and trying to find insane ways to implement things I thoroughly enjoy into lesson plans, and of course I feel like it wouldn't fly in a formal setting, but heck, why not. Rage comics could be the next generation's graphic novel, and perhaps for creative classes this could be utilized effectively. Who knows?