A group at Stanford has created an interesting new camera using a combination of conventional camera and a microlens array to form a "plenoptic" camera. This link hit our photography mailing list yesterday, and I spent some time reading it. It's really quite clever. Basically it uses the microlens array to serve as thousands of tiny lenses. Each of these "sub-lenses" images the target scene over a narrow field of view from a different spatial location. Then, computer software can take these individual images and recombine them in flexible and clever ways: allowing you to refocus images, shift perspective, and all sorts of other cool ideas.
Very neat stuff.