No more moaning regarding claims aware SharePoint please. What you need to know is right here.
Configure Web SSO authentication by using ADFS (Office SharePoint Server). http://technet2.microsoft.com/Office/en-us/library/61799f9a-da01-4c11-b930-52e5114324451033.mspx?mfr=true
Oh and by the way, if you were considing a third party "SSO" solution for SharePoint.... ahh, no perhaps this is not the place for such a sentiment... :)