http://www.brisnet.com/php/AprOnline/index.php
I just came across this today. No strings attached free database until Jan. 31.
Search by dam or foal,complete race records.
Completly interactive. I followed Ruffian's lone sister Laughter's female line finding Coronado's Quest as well as Private Terms.
Take advantage while you can, I wish I had seen it sooner.