Bing for iPhone App has a feature called "Social search," where you can search through your Facebook and Twitter accounts on your phone and see combined status updates from your friends. If there's an instant answer available, the app show you that first, followed by social results. This social feature comes in handy when you're looking for movies or restaurants and want both information from the web and opinions from your social network.
Here's how to get social results: » From home page, click "Social" » Then connect your accounts. Now when you search for anything, relevant results and your friends' social network mentions will also appear » Finally if you find something you like using the app, you can easily share it with Facebook, Twitter, or through email.