The 'Don't Ask Don't Tell' policy was repealed.
SpaceX became the first private company to launch, orbit, and recover a spacecraft.
A first edition of 'The Birds of America' by John James Audubon was auctioned at Sotheby's, London, England, for £7,321,250 ($10 million) – which took the record for any book at auction.
British singer-songwriter Adele released her hit single 'Rolling in the Deep.'
Harry Potter and the Deathly Hallows – Part 1, based on J.K. Rowling's 2007 fantasy novel, was released worldwide.
Taylor Swift's third studio album 'Speak Now' was released. It won Billboard's 2011 Album of the Year.
All 33 miners trapped after a mining accident in Chile were rescued after being stuck underground for 69 days.
Instagram was launched and gained 25,000 users on its first day.
Actor and actress Seth Rogen and Lauren Miller got engaged.
The American biographical drama movie 'The Social Network' was released at the New York Film Festival.
Lady Gaga wore a full outfit made of meat for the MTV Video Music Awards.
The historical drama 'The King's Speech' premiered at Telluride Festival in the United States.
Singapore opened the world's first Summer Youth Olympics Games.
Californian Judge Vaughn Walker overturned the same-sex marriage ban.
Wikileaks published classified information about the war in Afghanistan.
British boyband One Direction was formed during X-Factor UK.
'Inception,' starring Leonardo DiCaprio and Joseph Gordon-Levitt, premiered in London, England.
The longest tennis match in history took place.
The Twilight Saga: Eclipse premiered in Los Angeles.
Eminem released his 7th studio album ''Recovery."
South Africa played host to the first FIFA World Cup in Africa.
SpaceX's Falcon 9 rocket successfully launched on its maiden flight.
In the Super Rugby Final at Orlando Stadium, the Bulls defended their title with a 25-17 win over the Stormers in an all-South African final.
The final episode of LOST aired.
Emmy Award winner Julia Louis-Dreyfus, star of 'Seinfeld,' received the 2,407th star on the Hollywood Walk of Fame.
Craig David was appointed as Goodwill Ambassador against tuberculosis (TB) by the World Health Organization.
WikiLeaks published the first US diplomatic cable leak provided by Chelsea Manning.
Casey Neistat uploaded his first-ever YouTube video.
Justin Bieber reached one million followers on Twitter.
Steve Jobs announced the Apple iPad, the company's most advanced piece of technology at the time.
A 7.0 magnitude earthquake in Haiti claimed 160,000 lives.
Judge Simon Cowell left American Idol but continued working with FOX on X Factor US.
Giant self-rolling snowballs were found in the UK.
The world's largest building at the time opened in Dubai.
