If an iPhone is configured to sync with Exchange, what's the best way to break that connection while preserving all the contact and note data on the phone? Is it enough to remove the Exchange account and then sync with Outlook directly? Or are there other gotchas with that?
You can't; Exchange is an all-or-nothing deal. The only way to keep the data would be to export it to another service (e.g., MobileMe, Yahoo, Gmail, whichever works), break the connection, and then reimport the data into your regular contacts.