Happy 5th Birthday, Twitter! 10 Top Tweets of the Past 5 Years

March 21, 2011— -- The micro-blogging site Twitter is hardly micro anymore.

Since its launch five years ago today, the social media start-up has shown the world just how powerful 140 characters can be.

It has taken down governments, while lifting Hollywood stars to new heights. It has brought accountability to institutions, while giving individuals a new platform for action.

Over the past five years, single tweets have led to marriage and divorce, fame and notoriety, revolution and rebuilding -- here are 10 of our favorites.

@Jack: inviting coworkers

It was the tweet that launched a social media revolution. According to Twitter, this is the first official tweet sent out by the company's co-founder Jack Dorsey on March 21, 2006.

@barack obama: We just made history. All of this happened because you gave your time, talent and passion. All of this happened because of you. Thanks

Posted by President Barack Obama (or the individual who manages his Twitter account), immediately after his 2008 victory, this tweet speaks to the role of social media in that presidential election. Through Twitter, Facebook, Flickr, Youtube and other new media, Obama and his party rallied young people across the country. Since the election, Obama's White House has continued to use social media to reach citizens directly.

@jkrums: http://twitpic.com/135xa - There's a plane in the Hudson. I'm on the ferry going to pick up the people. Crazy.

When Janis Krums of Sarasota, Fla., posted this tweet and picture, in January 2009, of the U.S. Airways jet landing in New York's Hudson River, he didn't just capture the so-called "Miracle on the Hudson," he caught the attention of the media. The iconic image was among the very first pictures of the event seen by the public and reinforced the role of citizen journalism and Twitter's growing influence.

@aplusk: "Victory is ours!!!!!!!!"

Maybe it took Charlie Sheen only 24 hours to attract 1 million followers on Twitter, but back in 2009, Twitter followers weren't so easy to come by. It took actor Ashton Kutcher more than three months to reach 1 million follwers and he was the first Twitter user to reach that milestone. In the lead-up to his first million followers, the media and Twitterati buzzed about the "race" between Kutcher and CNN (his closest rival). This is the tweet Kutcher posted when he crossed the million-follower mark.

#iranelection

It was the revolution that wasn't just televised, but tweeted, too. In June 2009, the violence in Iran following the election was tweeted, blogged, streamed and posted on countless websites despite government censorship attempts. According to Twitter, #iranelection was the top trending news topic in 2009.

@Astro_TJ: Hello Twitterverse! We r now LIVE tweeting from the International Space Station -- the 1st live tweet from Space! :) More soon, send your ?s

In January 2010, Twitter officially went extraterrestrial. This tweet, made by NASA flight engineer T.J. Creamer from the International Space Station, was the real-time tweet sent from space.

@conanobrieng: Today I interviewed a squirrel in my backyard and then threw to commercial. Somebody help me.

After comedian Conan O'Brien lost the so-called late night wars and his position as the host of NBC's "The Tonight Show," in February 2010, he took to Twitter to reach his fans. This was his very first tweet. O'Brien's account quickly exploded with followers, but his wasn't the only online profile Twitter helped boost. O'Brien famously follows just one person on Twitter, Sarah Slowik (@lovelybutton), who now has more than 42,000 followers herself.

@BPGlobalPR: Catastrophe is a strong word, let's all agree to call it a whoopsie daisy.

In the aftermath of last year's devastating oil spill in the gulf, this fake Twitter account mocking BP's public relations team took the Internet by storm. The parody account swiftly gained a following on Twitter with its satirical take on clean-up efforts in the gulf. This tweet was considered one of the year's most powerful tweets by Twitter, in its 2010 "Year in Review" report. It was this account, not the official BP Twitter account, "that defined the discussion--spoofing the company's attempts to improve its public image," Twitter said.

@sh*tmydadsays: Don't focus on the one guy who hates you. You don't go to the park and set your picnic down next to the only pile of dog sh*t.

By tweeting just one of his father's crass comments a day, Justin Halperin, a one-time struggling L.A. writer, has attracted more than 2 million followers, published a best-selling book and launched a television series. This tweet was the most re-tweeted comment of 2010, according to Twitter.

@nadiralamrad: @speak2tweet http://bit.ly/f6AGsC "Phone lines are being cut in the city centre…I can't reach friends there." #Cairo #Egypt #Jan25 #Tahrir

As with Iran, Twitter helped Egyptian opposition members reach one another and the world. As uprisings spread across the Mideast this year, Twitter and social media played a crucial role in helping people communicate despite attempts at government censorship. When people lost access to the Internet, engineers from Twitter, Google and Say Now worked together to launch Speak2Tweet -- a way for people to send recorded messages via tweets. This was one of the very first messages in which a Twitter user translated a Speak2Tweet message to English and shared it with the world.

ABC News' Niketa Patel and Dan Patterson contributed to this report.