Technology students at Duke University, Durham, US, have demonstrated an application that allows a mobile phone to be used as a pen to write messages in the air.

The PhonePoint Pen project is being developed by Sandip Agrawal, Ionut Constandache, Shravan Gaonkar, and Romit Roy Choudhury, and uses the accelerometer increasingly found in high end handsets for handwriting, or more accurately, hand gesture recognition.

After writing letters or drawing diagrams in the air, the gestures are turned into text on the handset and can be attached to photos or embedded in an email.

The idea is that the application could allow users to jot down notes or small pieces of information quickly and easily.

As you can see from the YouTube video, the phone pen works in concept, but the researchers have run up against two significant obstacles. The first is a lack of visual cues so the user can see how their characters are being formed, and the second is the lack of a gyroscope in mobile devices, meaning the handset cannot accurately translate rotation of the handset, unlike for example, the controller of a Nintendo Wii.

“Our basic prototype validates the feasibility of the pen. Our ongoing work plans to augment the pen with real time feedback, character recognition, and with better support for drawing diagrams,” said the students in a white paper on the project.