I keep thinking there must be a standard way to handle this situation. My contact managers (in the iPhone and GMail) want to divide the world into individuals. But I want to maintain contacts for couples too. That way if they share an address, children, or even (gasp!) a common land line phone number, I see it all in one place, rather than maybe here with her info or maybe there with his.
As a result I end up with three records: one for him, one for her, and one for the two of them. Birthdays travel with the individual, and anniversaries travel with the couple.
It’s a small enough annoyance, but what’s the canonical way to solve this?
Rambles Blog at Star Chamber 
I’ve been frustrated too and years ago put together a toy database to address some of the problems. The CSCW crowd did work in the area eons ago and there were some nice ideas that I’ve never seen in the widely available address books There was (is?) a project to make something useful called tuatara, but it seems to have run out of steam – it is also linked to google accounts and I don’t think I want to go that far.
If you find anything, I’d be very curious as I’m not happy with what I have.
Why stop at couples? I’m sure there are other groups and organizations that share addresses, primary phone numbers, calendars, etc. Of course then you’d have to determine, between yourself and your spouse, who is president and who CEO.