John Locke, a Columbia architecture grad, has set up a little conceptual experiment which he is calling the Department of Urban Betterment whose chief duty is to covert old pay phone boxes into tiny libraries.
Apparently he's set up two booths so far and had limited success. Apparently the first booth had all its books lifted, and then the shelves stolen within a few days. The second booth faired a bit better with pedestrians both taking and leaving books for while, but eventually it suffered the same fate as the first. Locke plans to continue his experiments but in future booths he wants to add some simple instructions to help show pedestrians the intended use.
Personally I love it, and I think that with a little education it could be a great addition to some neighbourhoods. Full interview with Locke available here