Newly Seeded Etacts (YC W10) Seeking Holy Grail Of The Unified Inbox
blogs.wsj.com
blogs.wsj.com
With that said, I don't know if adding another layer to integrate everything is the best solution. Instead of uncomplicated our lives, it just adds one more thing to manage.
I can see it being used by people with hundreds of contacts, but for the average user, it's probably not necessary, and perhaps overly complicated.