GOOG). But Yahoo! shares shot up $1.61, or 13.7%, to $13.36 on news of the Ballmer comment. Microsoft rose 6 cents, or 0.3%, to $22.72. Yahoo! "probably thinks it's still worth at least as much today" as it did in June, Ballmer reportedly said. But if Microsoft is intent on acquiring Yahoo! to bolster its share of online search and advertising to better compete against Google, it now has friends on Yahoo!'s board. In August, activist investor Carl Icahn won board seats for himself and allies Frank Biondi, former CEO of Viacom ( VIA), and John Chapple, former CEO of Nextel, which is now Sprint Nextel ( S).