I am trying to find a way to keep my address book in sync across my:
iPad
MacBook Air
MacBook Pro
iMac
Google Apps account
Gmail account
as well as my wife's
iPhone
MacBook
Google Apps account
Gmail account
(Aside: by "Gmail account" I mean a regular Google account, as opposed to a "Google Apps" account. Most people interact with it through their Gmail so I'll use "Gmail account" to differentiate between "Google Apps" and "Regular Google" contacts.)
Would you believe that the hardest part is syncing between Google Apps and Gmail accounts? Even if the accounts are linked via
