A million here, a billion there...

But what's a trillion?

We're hearing "illions" bandied about like Monopoly money lately. But what exactly IS a trillion dollars, anyway? And why should we care?

Because it's our great great great great great great great great great great great grandchildren who will still be paying it off, that's why.

Assuming the U.S. survives, of course.

For a knock-you-flat visual of a trillion dollars, check out this website.