Channel 4's Fact Check Blog is also pretty damned awesome.
But neither of them go far enough. I would actively pay for someone to fact check the major points of the Scottish Independence debate, because pretty-much everything I see is being put out by either one side or the other.
And it took several days for me to find out that while there was snow in Cairo, neither pyramids nor sphinx were covered in it.
And I only found out five minutes ago that Iron Maiden weren't actually tracking down music pirates to play to them, and then only because ajr mentioned it.
(Snopes kinda do this - but they don't do much on the political side of things, and they don't, for instance, have the Iron Maiden story yet.)
Original post on Dreamwidth - there are comments there.