Today: November 21, 2002 at 7:30:18 PST Stair-Climbing Wheelchair Evaluated By LAURAN NEERGAARD ASSOCIATED PRESS GAITHERSBURG, Md.- Stairs soon may no longer be insurmountable obstacles for some of the nation's 2 million wheelchair users. The first wheelchair that can climb stairs - plus shift into four-wheel drive to scoot up a grassy hill and even elevate its occupant for eye-level conversation - took a major step toward the market Wednesday, as advisers to the Food and Drug Administration unanimously recommended it be allowed to sell. But the panel backed a few limitations on the Independence iBOT 3000 Mobility System -...