Are there any services online that combine Bitcoin with David Chaum's blind signing protocol?
So far I am aware of only one,
http://blindbitcoin.com/ (and it appears down from where I sit)
The reason I ask about whether anyone else is working on bitcoin-backed Chaumian currencies is that me and a group of friends intend to start one, based upon Open Transactions, and are quite willing to cooperate, thus standing on the shoulders of giants if said giants are already present in the field of "blinded" coins
