Just about in the lines of Google Suggest ( i’m not sure if it is!) Yahoo! has launched a new search tool named ‘Search Suggest’ to provide suggestions for the relative search querries.
According to Kevin Lee’s Blog ( he is from Yahoo!) the suggestions are displayed when users start typing / in process to type the search word.
‘Search Suggest’ was already there Yahoo! Toolbar in Firefox but users need to select Yahoo! as there default search engine first.