You find a lot of cool stuff clicking around the TV Tropes Wiki. Here's two creepy short stories I stumbled across via some outbound links:
All the Myriad Ways, by Larry Niven. I've been crazy for alternate universe stories (Infinite Crisis, etc.) for years, but not enough of them get into the effects the knowledge of parallel Earths would have on the general populace. This one does.
Daphne and Her Dog, by Rebecca Sean Borgstrom. I've not much to say about this one save that it's a hilarious and terrifying deconstruction of a certain enduring piece of pop kitsch.