Matthew Robertson, Canadian proprietor of 'thews reviews, darkened his site in solidarity as well. I'm sure there were many other smaller sites than that did the same.
The rest of the sites that followed were all the 'big names' that advertised their intention to go dark as well.
Two variations on a theme were Ars Technica and Wired. Ars went black but spent the day writing stories about the issues surrounding SOPA. Wired put up a clever site that showed what was underneath the blacked out areas when you rolled your mouse cursor over the redacted sections. Ars stayed up to educate about the issues, and did a very good job. Wired stayed up trying to look cool and make money at the same time. Wired wound up looking 'tired' if not a little lame out of all the protesting sites.
- SOPA Resistance Day begins at Ars http://arstechnica.com/staff/palatine/2012/01/sopa-resistance-day-begins-at-ars.ars
- Protesting SOPA: how to make your voice heard http://arstechnica.com/tech-policy/news/2012/01/protesting-sopa-what-you-can-do.ars
- Why one game developer is skipping E3 to start an anti-SOPA crusade http://arstechnica.com/gaming/news/2012/01/why-one-game-developer-is-skipping-e3-to-start-an-anti-sopa-crusade.ars
- "Least restrictive means"? One way that SOPA could die in court http://arstechnica.com/tech-policy/news/2012/01/least-restrictive-means-how-sopa-could-go-the-way-of-copa.ars
- SOPA blackout spreads across the Internet http://arstechnica.com/gadgets/news/2012/01/sopa-blackout-spreads-across-the-internet.ars
- SOPA, Internet regulation, and the economics of piracy http://arstechnica.com/tech-policy/news/2012/01/internet-regulation-and-the-economics-of-piracy.ars
- A history of IP violence: how SOPA's and PIPA's sponsors have waged war on the Internet http://arstechnica.com/tech-policy/news/2012/01/a-history-of-ip-violence-how-sopas-and-pipas-sponsors-have-waged-war-on-the-internet.ars
- The Lonely Island gets off its boat to oppose SOPA http://arstechnica.com/tech-policy/news/2012/01/the-lonely-island-gets-off-its-boat-to-oppose-sopa.ars
- When a petition isn't enough: SOPA protestors raise money to hire lobbyist firm http://arstechnica.com/tech-policy/news/2012/01/when-a-petition-isnt-enough-sopa-protestors-raise-money-to-hire-lobbyist-firm.ars
- What does SOPA mean for us foreigners? http://arstechnica.com/tech-policy/news/2012/01/what-does-sopa-mean-for-us-foreigners.ars
- Even without DNS provisions, SOPA and PIPA remain fatally flawed http://arstechnica.com/tech-policy/news/2012/01/even-without-dns-provisions-sopa-and-pipa-remain-fatally-flawed.ars
- PIPA support collapses, with 13 new Senators opposed http://arstechnica.com/tech-policy/news/2012/01/pipa-support-collapses-with-13-new-opponents-in-senate.ars
- Hollywood fights Internet protests with... TV ad, billboard, radio spot http://arstechnica.com/tech-policy/news/2012/01/hollywood-fights-internet-protest-with-tv-ad-billboard.ars