Rovio has done the unthinkable--wait. Actually, this is exactly what the company would do when it comes to Angry Birds. Fans of the feather-flinging franchise can now pre-order merchandise from the Angry Birds online store. That way, super fans can be the first to receive the new items as soon as they release. Angry Birds merchandise has been somewhat of a mini-phenomenon to the already massive mobile (and soon Facebook) game developer, and now it can fuel even more excitement for ... Angry Birds flip-flops.