There is now a free Bing App for iPhone and iPod touch.
There's voice search that works great for map locations as well as old fashioned web search. Say "San Francisco weather," for a quick result, or even say a full address for a map or directions.
Bing for iPhone automatically finds your location, helps users discover a new spot by category such as restaurants, banks, theaters and choose whether you want walking or driving directions.
The mapping lets you, pan and zoom using Seadragon technology for some of it. Image search offers endless scrolling results (also works for any search result) and the ability flick through image previews and click through to the host site.
Other features include movies, news and flight status.