Nearly six months after the ginormous stimulus bill passed, politicians and economists are arguing about whether it has made much of a dent in the limping economy.

Defenders of the bill — President Barack Obama among them — insist it is too soon to tell because the stimulus hasn't had much of a chance to work. They have one key fact on their side — though it's a fact critics could just as easily use: Only $70 billion, or about 12 percent of the $580 billion in the spending portion of the stimulus package, is out the door so far. (It's much more difficult to track the tax cut portion, which makes up the bill's remaining $212 billion.)

Moreover, that 12 percent includes some $13 billion from the Social Security Administration in one-time $250 checks to current Social Security recipients. Those payments, while helpful for those who received them, represent the low-hanging fruit of stimulus spending, requiring no requests for proposals, no bidding process and no contracts to be tendered, invoiced and paid. Those Social Security checks make up almost one-fifth of the stimulus "spending" so far.

We’re going to continue tracking the speed at which money is being spent, as a key to how well the stimulus is working, updating our progress bar every week.