I can't really suggest any ideas. I mean, we're in the same business here, can't just give you my ideas.
I suggest keeping a notepad or using your notes app to record down anything interesting that you think of.
I don't believe that you can just run out of ideas.
I'm just kidding about not suggesting. How about something charitable? Do some funny skits in order to promote a charity, not the ice bucket challenge though. Stuff like what Funny or Die has been doing for a while.