In addition to an update to Bing app for iPhone, Bing is available as a default option on iPhone 4 and those who upgraded to iOS 4 software. It's really easy to reset your search default to Bing.
Here're the steps: "Tap "Settings" app (app with gears), Scroll down to "Safari" (iPhone browser), Tap "Search Engine" button, and Select Bing.
Try these new features on your Windows phone, iPhone, Android, Palm, Kin, or Zune HD today at m.bing.com: • Home page now features Bing image of the day (people love pictures) • Location detection through GPS on your phone (makes it easier to search for stuff near you) • Local Search with suggested listings nearby and category search (less typing, more finding) • Find places nearby, save them to a favorites list, and share that list with friends (plan your day all from your mobile phone) • Smooth panning and scrolling of interactive maps (who doesn't like a good mobile map these days?) • More details on local listings, like parking info, price, cuisine, and ratings (that's just Bing doing what we do, being a decision engine).