Yahoo's Panama - the context-based ad placement service that is supposed to return Yahoo to powerhouse glory - has been out a month, but CFO Susan Decker says Wall Street shouldn't look for an impact on Sunnyvale's bottom line until the second half of the year, AP says.

But it's already making a critical change in Yahoo's culture, CEO Terry Semel says.

Panama ''is now out and we are starting to smile again,'' said Semel, who is also Yahoo's chairman. ''It has changed the mood and tempo of the company.''

It needs to do both, analysts say. If Yahoo can't turn the ship around with Panama, Semel may need to start looking around for warmer waters. Either that, or an acquisition by Microsoft could be in the works.

Decker predicts Yahoo will make gains at Yahoo's expense.

"Our hope and expectation is we will see query share improve as our relevancy improves."