Typically, adding a keyboard to your mobile device arsenal means adding bulk and energy usage. A prototype touch surface keyboard shows that the near future may bring keyboards that will add almost no extra heft to your gear.
The prototype keyboard was built by CSR using Bluetooth Smart (also known as Bluetooth low energy) technology. The keyboard requires very little power, so lots of bulky batteries aren't necessary. The flexible touch-surface part of the device is less than 0.5 mm thick.
The obvious use for the technology development is as an extremely thin and lightweight keyboard, but it could also be designed as an extended touch surface that can respond to swipes, pinches, or stylus input.
CSR is promoting the prototype as "the world's thinnest wireless touch interface." It's not quite paper-thin, but it's getting close. It will get an official public unveiling at IFA from September 6-11. CSR intends to work with developers on bringing the technology to market.