One flash app I saw had a buxom cartoon girl, very innocent looking, looking at you. She says "Hi! What are you doing? Are you working hard? It looks like you're working hard..."
She says this very softly, tempting you to turn up your speakers.
Then she gets a disgusted look in her face, and screams "OH MY GOD, YOU'RE LOOKING AT PORN! FILTHY, DISGUSTING PORN!" all the while, about thirty pop-ups fill your screen, all of the same chick. It's pretty well done, actually, as the chick isn't naked, it just has her 'O' face.
I think the site went down a long time ago, last time I tried it it wouldn't work.