Microsoft has launched its official Bing App for iPhone and iPod touch. It offers much the same features as the versions already available for Windows Mobile and BlackBerry.
As with the web-based version, you will be able to do web searches, get flight and movie information and more. It also includes location-aware features (including turn-by-turn directions and traffic information) and voice search capabilities. You even get the different background images with clickable hotspots.
The Bing App is available for free from the Apple App Store or by going to m.bing.com (which will redirect you automatically to the App Store).