At this point, SOPA needs no introduction. But if you've been diligently ignoring it up until this point, good luck getting through January 18th as an uninformed citizen. Google, Wikipedia and a host of other websites are either going dark or making huge, unmistakable statements on their homepages in protest. Google's tagline? "End Piracy, Not Liberty." Pretty much says it all, really. If you've spotted another site rebelling today, shout it out in comments below — and while you're in the sh…