[Guest post by Noam Scheiber:]

Interesting bit of trivia from a blogger named "madhedgefundtrader," posted on the iconoclastic finance site Zero Hedge (via Politico's Morning Money):

Before he left, I pulled out all the cash in my wallet and pointed out to Geithner that while I had bills signed by previous Treasury Secretaries Larry Summers, Paul O’Neil, and Robert Rubin, I lacked one with his illegible scrawl. Did he have any which he could exchange with me? He sheepishly admitted that while such bills existed, they we[re] being held back from circulation until the Treasury’s existing stockpile of Hank Paulson bills ran out, in order to deliver taxpayers good value for money. I would only see his bills once the economy recovers and the growth of M1 starts to accelerate.

It's actually kind of a telling characterological detail...

Also, if you're wondering why I'm burying the lede by not explaining why Geithner was meeting with some dude called "madhedgefundtrader"--it turns out he's a longtime financial journalist-cum-money manager who knows Geithner dating back to his days as an assistant Treasury attache in Tokyo.