The Mobile Gadgeteer at ZDNet has some amazing video of the Readius eInk mobile reader, which folds up into something that looks about the same size as a bulky cellphone or first-generation mp3 player. The text appears to be very similar to the Sony e-book reader (although faster, as the video notes), but the amazing part is how easily it folds up at the end of the video. If you’re impatient, fast-forward to about 2:08.
[youtube https://www.youtube.com/watch?v=BVPSmbJf8aQ&rel=1&border=1&w=425&h=373]