The text box just above your contact list is the new Contact Search Bar. This is the new search field. When you type in this box, Yahoo! Messenger with Voice will match what you're typing with the contact details for those people on your list. If any content matches any friends, or user ID contact details in your address book (like telephone numbers, first or last name), Yahoo! Messenger will automatically identify entries and list them below the text box.
Our goal is to speed up your ability to contact your friends. We have to work together to accomplish this. Please make sure that all the contact details are entered accurately, especially the format of the telephone numbers so you can utilize our new Yahoo! Phone Out service quickly and easily.