Consistency is really hard quality to achieve and even more to maintain. Here goes a suggestion for all of you who have a large contact list in your address book and want to organize it: Plaxo.
It allows to easily unify your contacts across sources, proactively updates contact info, and syncs your complete address book.
Besides the contacts book it has backup and synchronization tools, calendar, and also Plaxo eCardse to send a contact card
