Windows Phone is unique OS in its own way and offers pretty smooth user interface but the only problem it had was the lack of universal search option. It had different search options such you could search for contact and in the People app etc. You had to go to specific app or section in order to search something. But it is believed that new Windows Phone 8 will take care of this problem as it is touted to have integrated with universal search option.
According to different screenshots and rumors the Windows Phone is said to have universal search which is appears to be pretty good. It will show you results from different apps, contacts, messaging, games, music etc but what makes it pretty good is its ability to show results even from your web including your contacts, the Marketplace and the like. It is still a rumor and we are not sure whether it will this good or not but the images that are surging manifest such option.
Rumor has it that you will be able to use the universal search from the Start screen but it is still vague whether it will be part of Bing search or not. If we consider the functionality of Windows Phone 8 like that of Windows Phone 7 then the physical button would be used to launch the Bing search app and software buttons would be used to launch any other search. We anticipate to see both these options joined together as it was seen in Android 2.x.