Choose how to answer an incoming call
iPhone users will like this: When you get a get a call you can't answer, you now have new options besides ignoring the call or sending it to voicemail (double-click the power button to do that). Tap the phone icon to get two new options: Reply with Message and Remind Me Later.
The Reply with Message option sends any of several canned responses (such as "I'm on my way") via SMS or iMessage; choose Custom to type in your own reply in the Messages app.
The Remind Me Later option lets you have the iPhone remind you an hour later, when you leave your current location, when you get home, or when you get to the office (if you've set those two locations in your Contacts card).