Let me count the ways! Pictured is the number one reason to buy Lightroom2. You can mask any part of your image. (3 shown here) When you hover over a dot, it shows the mask you’ve drawn in that area. You can then add or delete parts of the mask as needed. You can be precise as you like by increasing or decreasing the size of your brush.
Once your mask is ready, you can then use any of the sliders to adjust as needed. If you prefer, you can drag a scrubby slider right on the screen to make the adjustments! Very cool. So what’s so great about all this? The huge advantage to using LR2 is that all your adjustments are just EXIF!