Obama Mum on Vice Presidential Pick

Sen. Barack Obama has picked a vice presidential running mate but he isn't telling.

"I want somebody who is going to be able to challenge my thinking and not simply be a 'yes person' when it comes to policymaking," Obama told the CBS "Early Show".

The quality most important to the presumptive Democratic nominee? Preparedness.

"Can this person help me govern?" Obama asked.

But even though Obama has found that person, the much anticipated text message announcing his decision has yet to make it to the inboxes of political pundits and eager supporters across the nation.

"You are not going to get anything out of me on the vice presidential...nothin'," the candidate teased reporters on Thursday in Virginia.

Obama VP Pick Remains a Mystery

Obama is expected to appear with his running mate at a event at the State Capitol in Springfield, Ill., Saturday but remained largely out of sight as speculation swirled around three main contenders: Sens. Evan Bayh, D-Ind., Joe Biden, D-Dela., and Gov. Tim Kaine, D-Va. But the truth was, no one outside the campaign seemed to have any real idea.

"I think the fact that the campaign could hold the information so closely for so long says a lot about the Obama campaign ," Democratic consultant Tad Devine told ABC News.

"It says that there's a trusted circle of people around Senator Obama that he can trust and who have a lot of confidence and faith in him. It says that people on that campaign are not out promoting themselves at the expense of their candidates. And I think that's one of the reasons they won the nomination and it's a reason they are going to have a good chance at running a solid general election campaign as well. "

The media hunted in a flurry hunting for clues, staking out the homes of each so-called "short-lister".

Some industrious children who live across the street from Indiana Sen. Bayh have been getting quite a bit out of reporters via a lemonade stand, but Bayh himself refused to quench any thirst for information.

"You've been very patient," he thanked reporters, standing outside in the sweltering summer heat.

As journalists hunted for any clue even a dark horse candidate emerged -- Texas Congressman Chet Edwards who represents the district in which President George W. Bush resides.

But even Edwards, D-Tex., says he expects to learn of Obama's running mate the same way most people will: by checking their cell phone, blackberry or email.

When asked if he had signed up to receive the famed text message alert from the Obama campaign.

"Yes I did," Edwards said with a laugh, adding, "along with millions of other Americans."

Hoax Text Messages Taunt Obama Supporters

Several hoax messages have made the Internet rounds, including an alert falsely claiming Virginia Gov. Tim Kaine was the official pick.

Kaine, seemingly annoyed, acknowledged the false claim, "There's a lot of viral bizarre text messages going on."

Some might wonder why Obama's camp would consider making such an important announcement via text message or email. One possible reason may be to create a contrast between Obama and McCain, who admits to not using a computer.

In addition to projecting a certain image, the method of communication is also strategic: the campaign can use these newly-garnered electronic addresses to reach out to tech-savvy -- and mostly young -- voters on election night in the hopes of boosting voter turnout.

"This is gonna be another way to get the word out to people and say 'have you voted yet?" Dennis Culloton, a public relations expert, told ABC News.

But the build-up and suspense could backfire: if expectations are not managed, the announcement is at risk of being anti-climactic and letting down supporters as well as contenders.

But so far the campaign has been tight lipped about the process.

The candidate worked most of the day on his Democratic National Convention nomination acceptance speech at Chicago's Park Hyatt Hotel, while outside, the rest of the world -- supporters, possible picks and the press -- all waited and wondered.

ABC News' Avery Miller, Yunji de Nies, Matt Jaffe, Lisa Chinn, Jason Ryan, and Natalie Gewargis contributed to this report.