UPDATE: New research and blog here. Very interesting read.
Evidence Paper: DFID (UKAID)
Wiki: Cash Transfers overview
BBC News Story on India
My Ebook: Don’t give to the poor…
Clarification: It is more accurate to say about half of India’s population are unbanked (I said 2/3rds).
However a huge number of accounts opened as part of a campaign have never been used.