The site offers a free full-length downloadable GMAT-CAT test. This test lets you compare
your scores with those of other test-takers around the world. Offers excellent study
guides for various sections of the GMAT. http://www.crack-GMAT.com
2. GMAC.org
The official GMAT site offers a free GMAT CAT test on its site. http://www.gmac.org