Does the choice of Dayton, Ohio, for the first appearance provide any clue to the pick?

Republican presidential candidate John McCain has settled on a running mate, and the pair will appear together on Friday at a rally in Dayton, Ohio, according to Republican sources outside the campaign.

McCain will notify his choice on Thursday, one source said. The decision is closely held among just a handful of the senator's top advisers.

Speculation has centered on several candidates, including Minnesota Gov. Tim Pawlenty, former Massachusetts governor Mitt Romney and Sen. Joseph I. Lieberman (I-Conn.).

Here's hoping it isn't Lieberman. I might be able to live with dark-horse Tom Ridge, but I think that would be a bad choice as well. But does the choice of Dayton make it more likely that we will see an Ohioan like Rob Portman? I'm not sure -- though I would be happy with Romney, Pawlenty, Alaska's Sarah Palin or Virginia's Eric Cantor. And as I said yesterday, I don't think that Kay Bailey Hutchison would be a bad pick -- though I find it highly unlikely.

Closing question -- can the choice be kept secret until the announcement on Friday, or will it leak earlier? And will such a leack come before or after Barack Mugabe Obama's Nuremburg rally at Invesco Field?