The site's Bookify online bookmaking tool simply connects to your online Instagram collection and autoflows your most recent photos into a book; the one with most "likes" ends up on the cover. Blurb optimizes the images so they look their best when printed.
From there you can edit and preview the results before purchase, share, or sell your book from the Blurb.com bookstore. You get a choice of three cover types and five paper choices. A 7x7-inch book starts at $10.95 for a softcover 20-page book and goes up from there depending on paper, cover type, and page count.
For those of you who don't use Instagram (myself included), you can still use Bookify to pull photos from Flickr, SmugMug, Zenfolio, and Picasa, or upload directly from you computer.