News: Google has released a video preview of Google Glass, the voice-controlled wearable headset that lets users send and receive messages, take pictures and search the web hands-free (+ movie).

The video is shot from a first-person perspective as Google Glass wearers use voice commands to control the device.

By uttering the phrase "okay Google", followed by one of the recognised commands, wearers can search the web, take pictures and record movies.

Other features appear to include video chats, weather reports, map directions and an onscreen translation service.

Google has also announced plans to expand its pre-order programme to "creative individuals who want to join us and be a part of shaping the future of Glass."

The Glass Explorer initiative will allow the general public to try out the headset and offer feedback on how Google can develop the hardware and its features.

Hopeful applicants are invited to write up to 50 words explaining what they would do with the headset and post them on Google+ or Twitter along with pictures or short movies.

The #ifihadglass competition is open to US residents over 18 only, and selected participants will still need to purchase their own headset for $1500, plus tax.

John Hanke, head of Google Maps, recently told Dezeen that smart glasses and wearable computers will soon guide people through airports and shops and allow them to pay for goods and services. "In the future the whole transaction could happen through Google Glass, payment and everything," he said.

Last year we published a glimpse of Google's data centres around the world, which feature primary-coloured pipework and cooling rooms that glow green – see all Google projects on Dezeen.