Thanks Rudra - I agree a lot of filters are interesting to play with and may never be used again - but there are some that are invaluable. How many of us use Noise reduction and Unsharp mask without thinking? They are often the last two things we do to an image. I am not a technically good photographer, ie image in camera is pin sharp, exact dof, perfect lighting and white balance etc. Most of my stuff is "snapped" and needs some post processing. But what I find so useful about the Nik software is its precise control and how it does not spread into areas I wish to leave alone. Also it is non-destructive of the original. I would recommend people to follow the links to Nik in the first post and watch the learning videos.
I feel that these filters may be very useful to those who specialize in portraits, weddings etc because selective use may mean the difference between having an album/portfolio and not - particularly for those of us who cannot afford a camera tied to two 30" Apple Displays where each shot is checked in Aperture or it's equivalent as it is taken - face or dress slightly off? a quick fix of that part of the picture with the appropriate Nik filter saves time.
Here is a crop from the Spring in Bury post showing the older man and woman - their faces were "burnt out" a little and have been restored with Viveza.
Viveza1.jpg
place control point - size to face - alter saturation with live preview - done