A company called Pelican Imaging recently announced it had developed the first prototype “array camera” for mobile devices. Instead of using one lens, Pelican uses an array of multiple lenses; it combines all the data from these multiple viewpoints and then builds a single high-quality image.
The benefit is a thinner footprint (many speculate the iPod touch gets crappy camera’s because a better one can’t be fit in the device). The down side? I have no clue, but I would guess it will be a while before they match the quality and ‘feel’ of a regular image sensor.