A's need a pitcher, Giants need a roster spot. This takes care of both.
With Anderson's elbow going under medical review, the A's run the risk of losing yet another starting pitcher this year. Anderson could be joining Braden, McCarthy, and Ross on the DL, along with Rich Harden, who (let's be honest) no one thought would remain healthy for long this season. With Outman and Moscoso now starting games for the A's, we're now putting our #7 and #8 starters on the mound in the #4 and #5 spots of the rotation. Losing Anderson would be a massive blow, and would require something drastic to even attempt to minimize the potential damage. We'd need a pitcher who at least COULD pitch well, one with major league experience, maybe even some comfort in the Coliseum. Barry Zito might be the guy.
Of course, the Giants will have to eat most of Zito's $18.5M/yr contract, but that concept is nothing new to baseball. I figure the A's would pick up about $5M of this contract (pro-rated for this year), and the Giants would pick up the other $13.5M just to open up the roster spot for Vogelsong and put a tiny Band-Aid over the money-spewing wound of the Zito deal. I figure the Giants need Zito on June 28 for their double-header at Wrigley, but after that he's more than expendable and it's not like he can go back to the minors.
There are probably better pitchers out there that are available (especially after Zambrano's blowup in Chicago), and I'm sure there are cheaper ones too. But I remember when Zito pitched in Oakland, and pitched well. Maybe a return to his first major league club could be just what the doctor ordered.