The Public Library of Law just launched, and it reports that it provides free access to all Supreme Court cases, federal appellate cases from 1950 on, and state cases from 1997 on. You can also search through all these jurisdictions at once.
I still expect I’ll use FindLaw quite a bit, because FindLaw lets one link to cases from posts, and have readers be able to follow the links without registering. But PLoL’s coverage and search ability seems to be in many ways better than FindLaw’s, so I think I’ll be using PLoL quite a bit — and of course those who don’t have free Westlaw and Lexis will find PLoL more useful still.