Do you think the Main Street Express (John Edwards' outfit) offers some kind of frequent flier miles to journalists? I think I remember reading that the press corps actually reimburses travel costs when reporters travel with candidates or government officials (e.g. with the president on Air Force One). They'd be crazy to give up the chance at all those miles.

And for Huckabee, the article says this:
"He needs the frequent-flier cards because he travels on normal planes - US Airways for this trip. He needs the credit cards and cash because he pays for stuff. Some candidates have their staff handle the taxis and tips, but his national field director is his daughter, Sarah, so he's probably used to grabbing the tab."