I'm really interested at the moment in direct delivery to readers - to their homes or offices.
Netflix for Library Books by Tame the Web referred my to the exciting service offered by Topeka and Shawnee County Public Library. They don't shout about it on their website but placing a hold on a book on their system means getting that book mailed to your house AS DEFAULT! If you don't want this you can request a phone call and pick up the item at the library. There is no premium rate for this service and the options for returning the book include - in person to the library, to the drive-by book drop box in their car park and to a number of book drop locations in the city (these are not libraries, the one I looked at was a petrol station!).
Much more details on how it all works and what it costs is available in David Lee King's post on The Missing Piece of the Library Netflix Model including some interesting comments and questions.
This is a fascinating example of direct delivery in a public library setting and is my favourite example so far. Now I'm on the lookout for more...