#egypt topped the most used hashtags - groups of tweets gathered together around the same subject - indicating the momentous uprising against Hosni Mubarak's regime that triggered the Arab Spring.
This was followed by #tigerblood, referring to a comment made by actor Charlie Sheen following his sacking from US comedy Two and a Half Men. Sheen famously told celebrity gossip website RadarOnline: "My fangs are dripping tiger blood."
Sheen was also the most discussed actor on Twitter this year, after he hit the headlines for a series of often rambling rants on television and in the media.
After he joined Twitter in March following the controversy, Sheen attracted around one million followers in just 24 hours, thought to be a record for the blogging site.
Sheen's former show Two and a Half Men was the second most talked about TV programme, behind Pretty Little Liars.
Many of the most discussed people on Twitter this year were those who had passed away, including Jackass star Ryan Dunn, British character actor Pete Postlethwaite and screen icon Elizabeth Taylor, who was the most mentioned actress.
The resignation of Egyptian president Mubarak was the most talked about world news story, followed by the US special forces raid that resulted in the death of Osama Bin Laden and the Japanese earthquake and Fukushima Nuclear disaster in March.
Wayne Rooney was the most discussed football star in a list that surprisingly did not include Ryan Giggs, who was unmasked by Twitter users earlier in the year as being behind a high-profile super-injunction over an alleged affair.
Topping the most popular tech topics was the launch of Apple's new Mac App Store in January, while rumours that McDonald's was preparing to serve the McLobster sandwich in the US led the trends in the foot category. The luxury food was previously only available in Canada.
The music list was headed by Rebecca Black, the teenager who was propelled to worldwide fame after her debut single 'Friday' attracted less than flattering attention when it was posted on YouTube. Nate Dogg and Gil Scott Heron, who both died this year, also appeared in the top five, but there was no place for usual favourites Beyoncé and Justin Bieber.
The full rundown of the most popular Twitter topics of 2011 across movies, sport, tech, TV and other categories can be viewed here.
"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," said Twitter in a blog post on Sunday.
"More than anything, these trends demonstrate how Twitter connects people with common interests. Instead of watching the news, the Super Bowl and Pretty Little Liars 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."
In 2011, Twitter hit 100 million active users and also welcomed a number of high-profile people, including Simon Cowell, Gwyneth Paltrow, Salman Rushdie, Gary Barlow, Steve Coogan's Alan Partridge character and even the Pope.
MPs also backed a motion in October allowing them to use Twitter on their smartphones and tablet computers during Commons debates, integrating the microblogging revolution into UK politics.