...there was the Gemini Special Edition clamshell iBook.
The owner bought it as a parts machine to salvage some regular clamshells, but couldn't bear to "part it out." He thinks that it may have been an officially Apple-authorized device created primarily for disabled people, featuring added ports for a wheelchair joystick, switch and top-mounted USB. The Gemini also includes a second speaker – the standard clamshell iBook had only one.
Specs:
It's for sale on eBay.