Yahoo has upgraded its iPhone app to feature Voice Search. Much like Google's iPhone app (which introduced voice search about six months ago), Yahoo's oneSearch allows you to simply press a button and say what it is you want to search for. Through built-in feedback, the system generally adapts to each user's voice over time. Voice search is great for restaurant listings, sports scores, movie times, flight status, and other similar uses.
Yahoo's app consolidates everything you need from them into one place with oneSearch. You can get your news, email, Yahoo Messenger, video, etc. In many ways, now that it has voice recognition, it is almost identical to Google's app, making deciding which one to use a personal preference.
Yahoo was originally working on an application that would work universally for all smartphones, but that idea was abandoned when the company decided to focus its efforts on a mobile web browser for the iPhone. The application, which was already available for Blackberries, is free and available for download on the Yahoo! Mobile Website.