If Apple had decided they wanted our business, we'd have built our family portal solution around .Mac (dotMac). Alas, Apple decided they needed to focus on other projects; .Mac has languished for years.
The next best option is Google Apps. Email that integrates seamlessly with desktop email (no imap yet), Page Creator, Docs and Spreadsheets (soon presentation), Chat, Control panel - it's a persuasive suite backed the most powerful and fastest thinking megacorp in history. I assume they'll integrate Picasa web albums into their emergent family solution and it will be a small step towards their personal health record solution.
The cost is low -- basically $10 a year for their eNom managed integrated domain. I have the faughnan.com domain, but it's awkward to switch over. I decided for now to create a new family domain.
Now I'll see how well various outlook and iCal sync to Google Calendar solutions really work. There is still the nerdvana of an integrated family and work/home calendar solution in my dreams ....
PS. Privacy? Surely you joke. That battle was lost in America 15 years ago. If you want privacy, use paper.