An Apple patent filing reveals a technique that would allow certain components of a device to be concealed until needed. The patent suggests that components could switch between transparent or opaque states, with the user instructing the device to reveal a component, which could contain a biometric sensor, image capture device, or strobe flash, among other possibilities.
Regarding the prospect of a concealed biometric sensor component, recent news indicates that Apple has been actively investigating fingerprint recognition technology. Apple recently struck a deal with Microlatch, a company that has patented technology for registering fingerprints on a device for financial transactions, and in July, Apple agreed to purchase AuthenTec, a company that makes chips for mobile phones, fingerprint recognition, and near-field communication. [via Patently Apple]