Perhaps you've heard about Toxic Assets in the news. During the housing boom of 2005, the global economy invested in the US housing environment, which seemed absolutely risk free to everyone involved. Yes, sometimes people fail to pay their mortgages, but if they did, you could foreclose, get a house, and sell it really easy, because the financial markets were flooded with cheap credit. A Los Angeles area graphic designer has a two part series with an excellent demonstration of the details.
So now there's the crisis of everyone with the financial ability to owning a home, banks being stuck with legions of homes that they cannot sell, and people walking away from their homes because they're not as insanely valued as they thought they were, which worsens the "legions of homes" thing.
These useless mortgages are called "toxic assets" because the bank has invested huge amounts of money in them and cannot do anything whatsoever with it. To use a Thai expression, they're a "white elephant." (This was based on the old Thai custom of ruining a nobleman you hated by giving him a pretty white elephant. The elephant sucked money, but it was blasphemy to sell it, use it for work, or do anything productive with it. So they were stuck feeding something that they could not recoup in any way.)
I think I, or someone like me, should buy a few of these (at a standard "loan buying" rate.) It can go two ways, and either way I win. If the homeowner pays off his mortgage, I get more money, so I win. If the homeowner defaults, I get the house. I want a house, so I win.