Yes, I know we can't give all details, but I think we can get in touch through the Digit forum members atleast.
The idea is this
We post only the Blood Group and City
Like mine - B+ , Cochin, Kerala -only that much. no name, phone num, email - nothing.
Now, if some forum members are in need of blood, actually he need not be a forum member, but someone who know a forum member (through them they cn post) can post - We are in Cochin, in need of B+ blood, and of course, they can tell how to contact them or they can send a request in forum and like another member mentioned, can contact through PM.
Making another website may not be a good idea, but as we are all friends here and majority of us ready to donate blood, I think my idea is still valid and its not that bad !
Well, leaving it to all other members.