On the back of a request to find a one-switch method for reading Kindle books on a PC, I got in touch with the highly talented William Pilgrim and Tim Brogden. Both turned up two excellent solutions to the problem, and both allow one-switch users to browse up and down the pages of Kindle, PDF and Word documents. You can also use this method to scan up and down web-pages.
The simplest version to get going is William Pilgrim's: One Switch Reader. Set your switch to act as the key "1", and you'll have the power to page up, page down and slow-scan (a line at a time) through a document or web-page, aided by an arrow indicator. Happy reading.