Does anyone know of a free Screen Capture program for MAC like "printKey 2000" for PC's?

Mac OS X already includes quite capable screen-capture utilities. I don't know what version of Mac OS X you have, but the shortcut keys are, if memory serves, the same in most versions:

http://docs.info.apple.com/article.html?path=Mac/10.7/en/mh26782.html

You can also use the Grab application which should be present in the Utilities folder.

Regards.