Headline: "Obama may announce running mate later today"

Alternate headlines: "Obama may announce running mate later this week," "Obama may announce running mate sometime soon," and "Obama may announce running mate after he finishes his vegetables and puts his toys away" are standing by for possible later use.

Ha. I kid. The AP (yeah, I know) is reporting that he's holding a rally to introduce his Veep tomorrow.

WASHINGTON - Presidential candidate Barack Obama said Friday the running mate he has chosen — but has not yet announced — had to meet three standards to join the Democratic ticket: Prepared to be president, able to help him govern and willing to challenge his thinking.

Those criteria did little to narrow the guessing game as Obama prepared for a massive rally in Illinois on Saturday to present his No. 2 to the nation and undertake a pre-convention tour of battleground states. He planned to disclose his choice through text messages to supporters, perhaps as early as Friday.

Speculation is rampant!