I don't have ten, but here are my top five picks and reasoning:

1. John Edwards: An excellent pick to win over the white working-class vote that Obama has struggled to capture, without all the baggage that Hillary Clinton would bring. As a bonus, Edwards's new, angrier persona will serve him well in the "attack dog" role that veep candidates traditionally fulfill; and having already made a run in 2004, Edwards no longer seems like such a callow youth in the public eye. And with Edwards on the ticket and Obama's overwhelming support from black voters, North Carolina becomes a likely target. The downside is that he opens up Obama to the charge that he's too far left of center.

2. Michael Bloomberg: A great way to boost Obama's centrist appeal, and since Bloomberg is now an independent, picking him wouldn't have quite the sting for partisan Democrats that picking Chuck Hagel would. Bloomberg also has a lot of credibility on the economic front, which is a very handy thing to have under the shadow of recession. And he's old enough to provide a sense of gravitas. Unfortunately, he doesn't have any home-state assistance to offer; New York will go for Obama whether Bloomberg is on the ticket or not.

3. Evan Bayh: A bone thrown to Clinton supporters, without having to actually take on Clinton herself. Being a red-state Democrat, Bayh can help shore up Obama's centrist credibility, and he could conceivably put Indiana into play. No real negatives, but not as many positives as some of the others.

4. Chuck Hagel: If Obama wants to show his ability to reach across the aisle, as well as lending some weight to his talk of a new kind of politics, there's no better way to do it than to pick a Republican. And, like Bloomberg, he's an older man, reassuring to those who worry that Obama is too inexperienced. He's also a Vietnam vet. On the other hand, the Clinton wing might be outraged that their candidate was passed over for a member of the other party. Nebraska is pretty red but has shown signs that it might be open to supporting Obama. The question here is whether a cross-party ticket will pick up more independents and Republicans than it loses in partisan Democrats who decide to stay home.

5. Bill Richardson. Moderate Democrat, resume as long as your arm, lots of executive and foreign policy experience, and New Mexico is a genuine swing state, plus his name on the ticket could fire up the Latino community the same way Obama's fires up the black community. But does Obama really want to take on anti-black and anti-Hispanic prejudice in the same election? I think Richardson gets a juicy Cabinet post instead.