A twenty doesn't buy what it used to, but some rare 20-dollar bills can actually be worth a lot. Knowing what to look for can help you spot a bill that's special (and could be worth more than your car ...

Currently, the Federal Reserve issues dollar bills in seven denominations: $1, $2, $5, $10, $20, $50, and $100. While $500, $1,000, and $10,000 bills are no longer produced, they remain in ...