To make the text larger than 10-point font requires zooming in on the document and dragging it around with the iRex's stylus, a naggingly slow process given E-Ink's refresh rate of about one second. iRex claims it redraws its screen faster than Kindle, but in Forbes.com's tests it locked up sporadically and often took far longer to refresh than Amazon's less flashy display.

FORBES: E-Books

This Cybook offers an inbuilt High Speed Ink System to process any action at a fast pace.

ENGADGET: Bookeen Cybook Odyssey HD FrontLight joins the lit e-reader fray

So far no bill has bounced between the Houses more than 15 times, but one constraint on the process might be finding a different ink to signify the exchange of amendments.

BBC: That most mysterious of Westminster rituals