Just a few years ago, anyone could get credit -- and for cheap. Banks were falling over each other to sell you a mortgage, and credit card offers clogged mailboxes across the U.S. But the world has changed. Easy credit ultimately gave banks a hard time. Losses from bad mortgages piled up as the housing bubble burst. As unemployment climbed, credit card defaults jumped. Banks pulled back in response and tightened credit, which means that it's more important than ever to make sure your credit history is as pristine as possible -- not only to qualify for a new loan, but also to obtain the lowest possible rates. Luckily, knowing where you stand is relatively easy and doesn't have to cost you a penny.