The AMT is an alternative minimum tax you can use in doing your taxes. Congress passed the AMT early this year, raising the income exemption to $46,700 for singles and $70,950 for married couples on this program. You must compute your tax bill using both the traditional code and the AMT, and then pay the higher tax. You would want to talk to a tax professional if you are considering using the AMT.
One tip though, big deductions can tip you into the AMT, so you may want to limit what you plan to write off. For example, wait until January to pay fourth-quarter estimated taxes to your state. You could pay them and deduct them on your federal returns, in December. You could also try to reduce your income in order to make the most of your exemption by maxing out your 401(k)s or asking your boss to put off any bonus (if you are lucky enough to get one) until early next year.
