Getting credit score information for free

Saturday's WSJ suggested the following sites to check out free credit score. 

http://www.credit.com

http://www.creditkarma.com

http://www.bankrate.com

Of the three sites, I found only creditkarma.com offering free credit score. Credit.com had the free score bundled with some other service. 

The credit score is an approximation as the agencies that provide the scores use custom formula that is not accessible.