Discription of Events: I was exiting the Beltway onto Rt. 50 -- had my blinker on and was slowing down -- when a guy in a Lincoln Navigator suddenly zoomed across two lanes on the Beltway to get to the exit, too, and he got RIGHT ON MY TAIL. He stuck his arm out the window and started waving it back and forth in a "shooing" motion -- obviously trying to get me to go faster and/or get out of his way (which I couldn't at that exact moment). As soon as I was able, I started to move to the other lane (which joins from the right), and he immediately tried to get into that lane, as well -- but when he realized he couldn't pass me on the right, he lurched back into the left lane and tore around me, just BARELY missing my car. The incident really shook me up -- that guy should be in JAIL!!