I remember many years ago thinking about how rediculous it was (well, seemed at the time) that people would pay good money for an ND filter.  It seemed to me that everyone was trying to speed up their shots, not slow them down.  The goal seemed to be taking good hand-held photos in dim light.

I think, for the majority, that is still true.  However, ND filters are now something that I crave.  Having seen so many slow, beautifully detailed shots of the sea, it’s now something I aspire to.

Take a look at this gentleman’s photostream (on flickr) to see some excellent examples!