After providing my feedback on Apple's new Maps app yesterday, I wanted to take the opportunity to praise a different feature: Facebook Contacts and Calendar on iPhone.
When I logged into Facebook, I was prompted with... nothing. Strange. So I headed to Settings where, sure enough, there was a Facebook option. After giving my email/password I had three options to use with my account. I'm sure that list will build over time as more apps take advantage of Facebook. For now, I'd like to focus on two: Contacts and Calendars.
But then I scrolled to the bottom of one card (pictured above), and what I found was a section called "Linked Contacts". Tapping on that revealed that I was actually looking at a combined view of the existing contact information (I use Google Sync/Exchange), and Facebook. So the app didn't re-write any existing data at all, it only layered information on top. Very cool.
Good job Apple and Facebook!