Attached Link: Greg Gorman Tutorial.

The method being referred to here as gradient mapping is the way originally put forward by Greg Gorman for converting digital images to black & white. (A few slight variations have crept in along the way).

For a PDF on how to set up a PS action for this method see the link above from Greg Gorman's site.

Photo Filter is something they added in CS2 - you are not missing out on anything though. It is merely a colour overlay with an opacity control, you can do this in PS7.

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html