Unlike the older PowerBooks, the iBook keyboard has full-size keys, making typing much easier. Along the top row are 12 slightly smaller function keys. The other six keys can be programmed to invoke other frequently used commands, such as launching favorite applications. The only way to attach peripherals is through the USB port. There is no ADB or serial port.
Converters are available.
Also, if more than one device is necessary, a USB hub, which allows several devices to use one port, will be needed. This may not be a critical issue for those with adequate space on their wheelchair trays, but it might hinder portability for ambulatory individuals with disabilities who frequently change locations throughout the day. Unlike the stereo equipped PowerBooks, the iBook has just one speaker. I do not believe this is sufficient not enough to use the iBook's voice output for augmentative communication, unless communication partners are close to the individual. It might not be loud enough for hearing impaired users either.