I'm watching the PR infomercial right now, and I just saw Pete photoread a health book, anyway - he just set something (I think it was a book, roughly two inches thick) under the health book, balanced it with his left hand and set it at about a 30ish degree angle... I just thought I'd share this.
Personally, I use whatever is handy to prop up a book - a table, a pillow, my hand...