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Twitter has revealed that Charlie Sheen and the Egyptian uprising were the most popular subjects for hashtags in 2011.

#egypt was the most used hashtag - a group of tweets gathered around the same subject - which shows how integral the site was to the uprising against Hosni Mubarak's regime that triggered the Arab Spring.

This was followed by #tigerblood, referring to a comment made by Sheen after his sacking from US sitcom Two and a Half Men.

Sheen had told RadarOnline at the time: "My fangs are dripping tiger blood."

The actor was also the most talked about person on Twitter, with his very public breakdown being chronicled almost exclusively by the site.

Indeed, such was Sheen's popularity that he attracted over 1 million followers within 24 hours of joining the site in March - a statistic that is thought to be a record.

Twitter posted a message on their blog which read: "Among other things, we saw history unfold in the Middle East, mourned the passing of Elizabeth Taylor, celebrated National Whipped Cream Day, and cheered for the Dallas Mavericks, Texas Rangers and Wayne Rooney. We wondered about Charlie Sheen, speculated about the Sony NGP, and raved (or raged) about Rebecca Black. And we tYp3ed LyK tHi5.

"More than anything, these trends demonstrate how Twitter connects people with common interests. Instead of watching the news, the Super Bowl and Pretty Little Liar at home alone, we watched them together on Twitter. We shared our thoughts about the world we live in, and we listened as others around the globe chimed in."

Twitter hit 100 million active users in 2011, and welcomed people such as Simon Cowell, Gwyneth Paltrow, Salman Rushdie, Gary Barlow, Steve Coogan's Alan Partridge character and the Pope.

Charlie Sheen behaving badly...