I am digging around to see if Titanium Desktop provides an outlet for adding a new contact to, or updating an existing contact in a native address book application. So, on the Mac that would be Address Book, and on Windows preferably Outlook's Address Book. Not sure on Linux… Thunderbird? We're looking at developing an app that has contacts needing two-way sync with local address books. What's the best way to go about doing this?
I might possibly recommend using Soocial if customers want to sync with their address books. Looks like this type of service, accessible through a web API, would allow us to save our contacts locally and then sync them to Soocial if the user configured that in their preferences. Soocial syncs with a ton of apps and gets us out of the equation of maintaining native sync code, for those that care about it.