Book dummies of the future?

A book dummy is a mock-up of a picture book containing sketches and text, used for planning a book and submitting it to publishers. (More here on picture book construction.)

One way to set it up (image by Bob Staake, whose work I first encountered as an impressionable yet wiseacre teen via the Style Invitational in the Washington Post)

Although some literary agents now accept manuscript submissions via e-mail, digital book dummies are, perhaps, not as straightforward. Maybe it's the large file sizes or the absence of physical page turns...or maybe it's just inertia. We book people like to hold paper in our hands.* Still, I expect dummies to go digital sooner or later. The technology is ready and waiting.

*On the other hand, we book people appreciate not having sore arms and backs from schlepping multiple 300-page manuscripts all over the subway and creation. An editor friend of mine recently got an e-book reader for looking at manuscripts, and boy, is she happy!