Leave it to American ingenuity. As more and more homeowners find themselves underwater -- that is, in possession of mortgages for greater amounts than their current homes are actually worth -- some are trying to improve their situations by selling their current homes at a loss and buying ones double the size for not much more money. Some experts say it makes a lot of sense, since homeowners can get out of bad, old mortgages and get into fresh, larger ones, without raising their monthly payment much. That's because home prices have dropped and interest rates have gone so low. Risky? Only if you believe the housing market won't recover for decades.