I put a wrist lanyard on mine (from a camera store), and I've figured out that if I run the lanyard across the back of my hand, and down between my index and middle finger, it supports the Reader's weight comfortably, and positions the page buttons nicely under my thumb. I just use my fingers to control the angle I'm looking at the Reader's page, not to actually hold it up.
Of course, different hand sizes and lanyard lengths will cause variance in how well this might work for others.
