The two strongest social network software providers for business users, Plaxo & LinkedIn, have produced a cross-network sync, so that Plaxo contacts can be synced with LinkedIn contacts.Clearly, if you have extrapolate the utility of this feature, then you'll want to tie many address books together.... ie around a single identity (well, a reduced number at any rate). I'm surprised it has taken this long to put this together - especially as their offices are about 3 miles apart.
