Got sent my first plaxogram today. Hmmm. I don't like this idea of being spammed with requests for contact information or having my contact details stored by a company I don't trust.
Trust and privacy are the key issues that needs to be solved with these kinds of centralized applications. I doubt any profit motivated company could be trusted in this role. It would be a great role for a public trust to take since the data protection could be be a core tenent of the founding charter. This could enable a slew of other applications that require the controlled sharing of personal information.
Meanwhile, I've permanently opted out of the Plaxo scheme.