Very exciting to see the UIDAI effort, which aims to provide a unique ID for every person in India, taking shape under the guidance of Mr. Nandan Nilekani as the first Chairperson. Kudos to him (loved his book - Imagining India) for bring this to life.
To better understand the impact a Unique ID system can have on various aspects of governance in India, go through the list of documents on the site, such as the relation between UID and PDS (Public Distribution System).