Wouldn't it be handy if when someone was speaking a foreign language, subtitles appeared just below their face? CNET reader Will Powell thought so, so he built some glasses that make you feel like you're in an arthouse movie.

Using some 3D specs, a couple of mics, a smart phone, a few cables and two Raspberry Pi mini-computers, Powell hacked together a working automatic translation system -- and he's made a video showing it working.

Powell, a programmer whose background is in Adobe Flex and AS3, was inspired by Google's high-concept Glass project.

"I can have a conversation with Elizabeth who speaks Spanish to me and I return with English," he explains. "I have never learnt Spanish but using the glasses I can have a full conversation."

The glasses are "completely transparent, so it looks like they are in your normal field of vision," says Powell -- like a pilot's head-up display. Using a Microsoft API, the system can translate 37 languages. The Raspberry Pis, running the latest version of Debian Linux, power the subtitle interface and the TV display.

The result is impressively fast for a home-baked project, although perhaps a little slow for a complicated real-life conversation. Elizabeth's English-accented Spanish may make it easier for the system to understand her -- real-life furriners might not be so precise in their intonation.

"The Vuzix 1200 Star glasses... are connected to the S-Video connector on the first Raspberry Pi and the Jawbone Bluetooth microphone that connects to a device such as a smart phone or tablet, to provide a clean, noise-cancelled audio feed," says Powell.

While Raspberry Pis are tiny, carrying two of them around, along with an S-Video cable and a couple of mics, makes the whole thing slightly impractical, but it's still a magnificent bit of garden shed tinkering. Nevertheless, if you want to reproduce Powell's project you can order as many Pis as you want now, and they're only £25 each.



"The Bluetooth microphone streams across the network what I say... This is then recognised and passed through Microsoft's translation API, with a caching layer to improve performance of regularly used statements. Passing through this API service is the biggest delay in the subtitles.

"Once translated, the server passes back the text and translations that are picked up by the Raspberry Pi driving the TV and glasses displays. Elizabeth uses a headset mic, but could use her own Raspberry Pi, glasses and Jawbone microphone to have the same experience as I do."

Fantastic stuff. Bravo to Will -- what's the coolest thing you've seen Raspberry Pi doing? Share your response in whatever language you choose down in the comments, or over on our cosmopolitan Facebook page.