Where are Photo Booth image files stored in Lion?

On Snow Leopard, photos taken with Photo Booth were stored in ~/Pictures/Photo Booth. They were individual image files that could be opened with any image editor. After updating to Lion, when I go to ~/Pictures, I see an icon for Photo Booth Library. When I double-click to open, it just opens Photo Booth with the thumbnail strip along the bottom. Where are those image files stored now? The whole point of them is to be able to use them for avatars, etc. which I can't do if I can't get at the individual files.