The team posted a Web demo of MobileASL on YouTube that shows the phones up and running on a Wi-Fi network. But, as Riskin was quick to point out, "the system is not ready for prime time."
The frame rate -- the number of frames per second -- is not very high, she said. "That's been our biggest challenge. We're focusing now on how we can cut more corners or take more reduced quality to get more frames per second pumped through there so that the video looks clearer."
Still, the project's Web site and the YouTube video movie has received more than 22,000 hits.
"I'm getting video-relay phone calls or e-mails every day, with somebody asking me, 'where can I buy it?' Ladner said.
The software has also received a fair share of attention from experts on assistive technologies for the deaf.
"As someone who was born deaf, I am very eager to see this technology finally coming to the U.S. after seeing it work firsthand in Japan and Scandinavia," wrote Alan Hurwitz, president of the National Institute for the Deaf at the Rochester Institute of Technology, in an e-mail.
Those who use sign language "will no longer be tethered to phone lines and cables," he wrote. "Cell phones will enable us to make calls in sign language from the car, on a camping trip -- wherever cell phone service is available."
The MobileASL researchers have been in talks with one cell phone company, which they'd prefer not to name at this early stage, about a commercial release in one to two years. "We're using Wi-Fi, but at rates that are low enough that a cell phone manufacturer could pick up the software and put it in their system," Riskin said. "That's what we hope happens."
That might be easier said than done.
There are about 37 million deaf and hard-of- hearing adults in the United States, which is a relatively small market, said Charles Golvin, a senior wireless analyst at Forrester Research.
The potential market for a service like MobileASL is actually smaller, because not all the 37 million use sign language.
"Deaf and hard of hearing people use a wide variety of communication modes, such as cued speech, and many use a combination of speech and sign," said Jay Wyant, president of the Alexander Graham Bell Association for the Deaf and Hard of Hearing, speaking through a video relay service. "A lip reader like me may not be able to use it until the bandwidth services improve."
And while such a technology might be a "noble idea," Golvin said, "the real question is whether there's an actual revenue-generating market opportunity for the carriers that would justify their investment in it. Two-way video is a very small market on mobile phones, and it's still small on the PC. It's like appointment viewing. I think a carrier would have a challenge with this service."
When asked about the feasibility of MobileASL, Mark Siegel, a spokesman for AT&T's wireless business, said, "It's hard to speculate, but we're always open to ways to help our customers communicate. We're always willing to take a look at something."
No matter what a carrier or company decides, the MobileASL team has considered other options.
"Maybe when the thing is finished," Riskin said, "we'll just throw it on the Web and say, how about it folks? And they can download it."