Some unsolicited advice to John McCain, who has been candid in the past about his lack of familiarity with financial issues and fiscal policy: name your Treasury Secretary nominee now, and put him or her on the campaign trail.
With the $700 billion financial bailout allowing nearly unfettered (and downright socialistic) discretion to the Treasury Secretary in fiscal regulatory policy, Treasury has become the most powerful cabinet department and its secretary will, with the president, shoulder primary responsibility for guiding the country--and the world--through the present crisis. The fact that McCain does not find fiscal policy to be a point of personal expertise should not doom his candidacy; his opponent has shown himself to be hardly an expert on economic issues, with his tendency to check and double-check with his financial advisors on the rare occasion that he takes a position on a fiscal issue. But it does make his choice for the position the more important, and he would do well to present that choice to the country as soon as possible. Naming his nominee in advance would give McCain a surrogate of importance rivaling his running mate, given the gravity of the current economic situation, and a surrogate who could speak with more fluency on financial issues.
As for who that candidate should be, McCain should steer clear of Warren Buffett, who he tends to mention first as a potential Treasury Secretary. Investing wisely in a down market, as Buffett has done throughout his career, is a skill, but it's not a skill particularly relevant to running the Treasury Department and setting fiscal policy. To the extent that name recognition is important, Mitt Romney or Steve Forbes would be better a choice than Buffett. More visibility for Romney, in particular, would provide a boost in the rust belt and upper midwest states, where McCain has struggled significantly since the crisis began.
McCain's approach to the financial crisis thus far has involved a proposal here, a less market-friendly proposal there, a suspended campaign, etc. Rolling out a person--a person respected within the financial community and the country at large--with a plan, preferably a market-based solution for a change, could finally give him a hold on an issue that has, to this point, evaded his grasp.