I came across Lulu.com
via the Google blog.
Not actually a site about the annoying singer, but a service that allows you to upload a PDF and have it published as a real physical book at no sunk cost. The book is then added to Amazon, Google Book Search and various other places automatically.
The actual cost of the book is the cost of production (about $5), whatever royalty you as the author want on top of that, and an extra 25% of the royalty as Lulu's fee. If no-one buys it you don't have to pay anything.
You can also publish e-books, calendars, CDs and DVDs in a similar way.
I really like systems like this that merge the web and other media together. I remember a (now defunct I think) Royal Mail service where you could send an email and have it converted into a real postcard
The site is also pretty ethical with a philosophy of ease of publishing without editorial conflict. It was founded by a guy called Bob Young, apparently, who also started an open source company, and it upholds many of the same ideas. You're encouraged to give your book an open source type license although you don't have to.
If only I had something to publish.