"Integration of various IM providers, has been done very well with Meebo, albeit only as a web app.
What I'm looking for is something that will take my various IM account credentials, social networks, phone and Mac Address book contacts, and then consolidate my contacts, with each contact containing their name, email address/IM user name on the various networks (Gmail, hotmail, yahoo), date of birth (from facebook), phone number (from address books), and usernames for the various social networks.
Then, if I wanna contact any of them, I look up the contact on that site. If the person is online on any of the IM/Social networks, it will let me chat with them from there. Otherwise, it'll show the email address and phone number, leaving it up to me to decide which medium of contact to use.
Lastly, it should sync the relevant consolidated data to all my softwares / devices. This is my dream web app"