Portable and Mobile Systems in Assistive Technology Introduction to the Special Thematic Session R. Manduchi 1 and J. Coughlan 2 1 University of California, Santa Cruz, CA 2 Smith-Kettlewell Eye Research Institute, San Francisco, CA 1. Introduction Computing power, communications and internet access are becoming increasingly untethered from the desktop and moving to the realm of portable, wireless technology. Devices such as mobile (cell) phones and PDAs (personal digital assistants) have become affordable and ubiquitous, and offer not only substantial computational power but also telephone and internet access, as well as a variety of sensors such as cameras, GPS and RFID readers. While the overwhelming majority of such devices are being marketed primarily to able-bodied users (primarily young, tech-savvy people without obvious disabilities), there is enormous potential to harness their capabilities for use in assistive technology. As of yet, however, this potential remains largely untapped, with very few commercially available systems of this type. Not only is this potential largely untapped, but many portable and mobile systems are particularly difficult to use for people with disabilities. For instance, Burton explains [1] that visually impaired persons “were left out of the loop when the evolution of cell phones brought display screens and other new advances, such as phone books, text messaging, and e-mail, into the mix,” initially resulting in “no text- to-speech functionality to accommodate cell phone users who are blind” and “no display screens with the visual characteristics, such as large fonts or highly contrasting colors, that would accommodate users who have low vision.” Similarly, other disabilities such as hearing and motor impairments make it very difficult for some people to operate cell phones and other portable electronics items, which often have limited audio capabilities and small, densely packed buttons. However, accessible mobile and portable systems, and extensions of existing systems, are now becoming increasingly common. For cell phones, a variety of accessibility options are now available, including text-to-speech output, screen magnification, audio amplifiers, hearing aid compatibility, and hands-free operation. Moreover, increasingly powerful assistive technology capabilities are being developed specifically for mobile and portable devices, such as the Kurzweil-National Federation of the Blind Mobile reader (www.knfbreader.com), which is a commercial OCR (optical character recognition) system running on a standard camera cell phone, and an MMS (multimedia messaging service)-based sign language system for cell phones [14]. The purpose of this special thematic session is to bring together experts in assistive technology and computer science to discuss possible applications of portable and