Photoshop :: Camera Flashes In The Background?

I've got an image of a guy in mid-air, halfway through a lay up (actually, the model was standing on a table, but that's neither here nor there!)

I separated him from the background, so the only thing I have is the model and the net on a black background, as if the image was a close-up photo. What I'd really like to do is add camera flashes to the background, so it looks like there's a huge crowd snapping pictures of the layup.

I've attached a small version of the picture so you'll have a better idea what I'm talking about.