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Microblogging website Twitter has changed the way people communicate - and in no more than 140 characters per statement.

New users flock to Twitter every day.

This year, among the notable names who got their own Twitter handles for the very first time are football legend Pele ( @pele), music icon Neil Young ( @neilyoung) and Pope Benedict XVI ( @pontifex).

The pope will send his very first tweet on Wednesday. As of Monday evening, he had more than 608,000 followers.

Twitter's Highlights of 2012

The 6-year-old San Francisco-based company says it has 140 million active users, all of whom send a total of 1 billion tweets every 2 ½ days.

Twitter released its highlights of 2012 this morning. Here's a look at some of the top tweets, searches and trends of this year:

Most Retweeted Tweet of the Year/Ever: The most retweeted tweet of the year was President Obama's simple election night message: "Four more years." He sent it along with a picture of himself hugging first lady Michelle Obama.

Within hours, people in more than 200 countries were retweeting the message, making it the most retweeted tweet of 2012 as well as the most retweeted tweet in Twitter history. The message had been retweeted more than 816,000 times as of Monday evening.

Runner-Up: The second most retweeted tweet of 2012 was sent by teen heartthrob Justin Bieber, who tweeted "RIP Avalanna. i love you" for his 6-year-old fan, Avalanna Routh, who died of brain cancer in September.

Before she died, the doctors and nurses who were treating Avalanna organized a pretend wedding for her and the pop star, and she was afterwards playfully known as "Mrs. Bieber." She even met the singer several times.

As of Monday night, Bieber's tweet had been retweeted more than 224,000 times.

Biggest Twitter Conversations of the Year

When Felix Baumgartner made his record-breaking skydive from space, people all over the world took to Twitter to witness the event unfold. During the year, Twitter was the gathering place for passionate conversation about sports, storms, scandals, tragedies and other topical issues, including these:

The U.S. presidential elections: The first presidential debate between President Obama and Republican presidential candidate Mitt Romney generated 10 million tweets. More than 31 million election-related tweets were sent on Election Day - hitting a peak of 327,452 tweets per minute, Twitter said.

The Summer Olympics: More than 150 million Olympics-related tweets were sent during the 16 days of the London Summer Games. The most discussed athlete of the games was Jamaican sprinter Usain Bolt. When he won the gold medal in the 200-meter sprint, Bolt-related tweets spiked to 80,000 per minute.

Farewell to Whitney Houston: On Feb. 11, the day the R&B superstar died, tweets about her death peaked at 73,3662 per minute. Nearly 2 million tweets were sent during her televised funeral on Feb. 19.

Other Notable Tweets of 2012

Superstorm Sandy from space: The International Space Station (ISS) captured live images of the storm as it tore its way up the East Coast. The astronauts tweeted live images to the world.

Primetime Emmy prank: During the Primetime Emmy Awards broadcast on Sept. 23, host Jimmy Kimmel as a joke encouraged the audience to tweet, "Oh my God, Tracy Morgan just passed out on stage at the Emmys. Turn ABC on now." Twitter users complied with Kimmel's wishes.

Tweets from Mars: NASA's Jet Propulsion Laboratory live-tweeted as the Mars rover, Curiosity, made its descent onto the Red Planet. The world received Twitter updates directly from the shuttle's command center. @MarsCuriosity has more than 1.2 million followers. A parody Twitter account, @SarcasticRover, has more than 105,000 followers.

Deepest tweet: On a dive to the bottom of the Mariana Trench in the Pacific Ocean, celebrated movie director James Cameron became the first person to send a tweet from 35,755 feet under the sea.