London: Micro-blogging site Twitter has revealed the most popular topics for tweets in 2011 -- #egypt and #tigerblood. The first refers to the unrest in Egypt and the second to a comment made by actor Charlie Sheen following his sacking from a hit US comedy.
The hashtag is used to group together tweets relating to the same subject.
Sheen made the headlines in 2011 for a series of public rants that culminated with the comment to online celebrity gossip site RadarOnline: "My fangs are dripping tiger blood."
He joined Twitter and had one million followers in the first 24 hours of his sacking, believed to be a record for the site, BBC reported.
He used the site to comment on the dispute between him and the producers of the "Two And A Half Men" show.
Twitter also released details about the hottest topics in a range of subjects, including the most talked about actors, countries and news topics.
The resignation of Egypt president Hosni Mubarak, which triggered a series of uprisings across the Middle East and North Africa, topped the news list.
It was followed by the US special forces` raid on Osama bin Laden`s hideout in Pakistan, and the Japanese earthquake in third place.
"More than anything, these trends demonstrate how Twitter connects people with common interests. Instead of watching the news at home alone, we watched them together on Twitter," Twitter said in its official blog.