Now that Sarah Palin has dropped her resignation bomb, the rest of the Web is spending a lovely Friday afternoon trying to figure out why. Matt Cooper has some theories, here. Friends Palin tell Politico's Mike Allen she plans to remain in the public eye, but hasn't decided anything about 2012. Is this a clue?

Balz talks to a lot of people, and no one has a firm theory about the resignation.

Halperin has 10 possible factors, most of which come down to money.

An Alaska blogger lists some possible reasons

Stromberg says this was a foolish move.

Alaska Democrats think she's crazy.

Bill Kristol thinks she's crazy like a fox.

And, of course, if you haven't read Purdum's Vanity Fair piece, it's definitely worth the hour of your life to read it.