This a test video captured by the iPhone 4 with a Canon EF 50mm f1.8 lens attached. It's pretty impressive.
The iPhone SLR Lens Mount we saw yesterday was awesome but it didn't actually work. As it was constructed, the iPhone would shoot right through the glass of the SLR lens. The guys at vid-atlantic, however, came up with a solution and have captured a rough video to showcase what an iPhone 4 with a real lens can do. It's not perfect, but it's pretty fun to see where this can go.