I missed the August 6th pre order window because I didn't know if I was gonna be able to afford it. Now I've got the money and I can't find pre orders anywhere. Does anyone know where you can still get them for launch day?

Sorry, but you probably should have preordered long ago.

You can buy one off Ebay, but expect to pay approximately $100-$200 extra.

Doing a quick Google shows the PS4 has been sold out (when it comes to preorders). So in short, to get one on launch day you either have to stand in a line and fight for one on launch day (assuming there are stores that kept a few units back and will put them out on the shelf), or buy one from someone else, like Shane C suggested.

Sony's probably producing them as fast as they can - they'll probably have another batch ready before Christmas. Maybe get on Amazon's notification list?

A quick google leads to this article, which suggests that Sony might be holding out some for retail stores on launch day.