Now you an Multi Contact merge in Gmail, not sure how this will work with facebook and whatnot.
But in Contacts menu in Gmail there is a "Find Duplicates" button.
Google Contacts Can Kill Duplicates in Bulk - Google Contacts - Lifehacker
But in Contacts menu in Gmail there is a "Find Duplicates" button.
Google Contacts Can Kill Duplicates in Bulk - Google Contacts - Lifehacker