Bar napkins may soon become obsolete as the medium of choice for scribbling down phone numbers now that a group of researchers is developing software that could turn a mobile phone into a mobile pen. Duke University researchers are finding new uses for mobile phone accelerometers through software that lets cell phone users write notes in the air using their handsets and have the text or images sent to an e-mail address.

Mobile phone makers have for the past several years built technology into their handsets that allow them to determine their angle with respect to the earth regardless of how they are tilted or turned. This is what lets smart phones such as the Blackberry Storm, HTC Touch Diamond, Apple iPhone and new Palm Pre provide a consistent screen display, regardless of whether the phone is held horizontally or vertically.

The original idea was to create a pen-like device that could convert writing in the air to digital text and images that could be viewed at a later time, says Romit Roy Choudhury, the Duke assistant professor of electrical and computer engineering overseeing development of the PhonePoint Pen application created by Sandip Agrawal, a senior student studying electrical and computer engineering at Duke's Pratt School of Engineering in Durham, N.C., and graduate computer science student Ionut Constandache. The researchers wrote the PhonePoint software specifically for Nokia N95 mobile phones (the company donated 30 to the project). *

The PhonePoint Pen application first captures the user's hand movements, whether drawing a picture, jotting down numbers or writing a sentence. The software is able to translate numbers and capital letters written in English (adding other languages is on their to-do list) into a message that can be e-mailed and accessed either from a computer or mobile phone. Pictures are saved as .jpg attachments that can be sent along with e-mails.

The students are working to expand the software so that it can recognize lowercase letters as well as cursive writing. The former requires greater character recognition capability. The key to enabling cursive, Roy Choudhury says, is letting the phone know when the user moves from one character to the next even though they are writing continuously.

It's unclear what the Duke researchers will do with PhonePoint Pen as they continue to develop the software. "Being a research group, we got engaged in solving a problem," Roy Choudhury says. "Now that we have something that works, we're not sure to do with it. We haven't thought much about marketing it."

See the video Agrawal and Constandache created to demonstrate their prototype.

Image © Raf Croonen

* Editor's Note (6/12/09): This article originally neglected to point out that Agrawal and Constandache used Nokia as their development platform.