If I had to spend my day humping dusty, oversized, scratchy burlap bags of coffee beans from the broiling interior of a steel container, I don't think I could work up much enthusiam for my next cup of joe.
@Art Monkey: Thanks very much. I have always adjusted levels and colors, but always only for the "value" variable (the most basic adjustment). Lately I adjust both levels and curves for each individual RGB channel and it allows for much better control of the colors.