Neutral Density Filter

After receiving Joseph's comment I looked up and decided to purchase the Nikon Neutral Density (ND) Filter!  I think it will be great to use on my upcoming trip to the Bahamas were everything is sunny, sky blue and water reflection!  The ND filter will help to modify the colors and can even help make the motion blur effects I was desperately trying to do at McWay Creek!

Can't wait to test it out!

Wikipedia shows the below examples of uses for the ND Filter:

Demonstration of the effect of a neutral density filter

Neutral Density Filters are often used to achieve motion blur effects with slow shutter speeds

Comparison of two pictures showing the result of using a ND-filter at a landscape. The first one uses only a polarizer and the second one a pol and a 1000x ND-Filter (ND3.0).