BoomTown once asked Microsoft CEO Steve Ballmer if the software giant was ever going to be able to catch No. 1 Google in market share in the increasingly lucrative search arena--despite years of trying and billions in investment in its Web businesses overall."We don't actually have to catch the leader," answered the pugnacious tech leader. "We just have to surpass the No. 2 to have a great business."No. 2 is Yahoo. And now, with a recently revamped search offering called Bing showing some promising signs, Ballmer shot another one across its bow by telling an audience yesterday that he was ready to spend billions more to win the race.