(CNN) -- To mark Nelson Mandela's birthday, we asked what the former South African president means to you. The response on social media has been overwhelming.

Leader, courage, hero, inspiration, freedom and hope were among the most often mentioned attributes in the thousands of responses we got on Twitter and Facebook.

Tweets and comments poured in from all around the world - those from Africa celebrated what "Madiba," (as he's commonly known) meant for their continent, while those from elsewhere said other leaders should try to emulate his example.

"Madiba reminds us what leaders of today are lacking (purpose). Gandi and Martin Luther lived, but Mandela is still living the struggles. Long live the people's hero. Long live Madiba 46664," Chinoye Emmanuel Ani wrote on Facebook.

"A legend, one who makes me truly proud to be African. Africa should be one nation with Mandela as president at any age. I'll take a 1000-year-old bedridden Mandela as my president any day," Facebook user Udoinyang SplyffVeron Itata said.

Other tweets and posts talked about how inspirational Mandela is to all generations. Susan Krischan Musial also wrote on Facebook: "I teach 3rd graders about South Africa through our Children's Museum in NY.

"They never fail to understand the connection of two great men - Mandela and King - making sacrifices for equality for their people and all people. Inspirational in the highest sense of the word."

His birthday also coincides with Mandela Day celebrations, a U.N.-led initiative started on his birthday in 2009.

This year, the U.N. launched a campaign asking people to mark the day by devoting 67 minutes of their time to helping others -- one minute for each year Mandela spent fighting for his cause.

"Nelson Mandela gave 67 years of his life to bring change to the people of South Africa," U.N. Secretary General Ban Ki-moon said in a special message.

"Our gift to him can -- and must -- be to change our world for the better. Today, I join the Nelson Mandela Foundation in urging each and every one of us to perform 67 minutes of public service on Nelson Mandela International Day," Ban Ki-moon said.

In a testament to his worldwide popularity, tributes and happy birthday messages were being sent all around the web all Wednesday, with people creating video notes, blogging and flooding social media with Mandela Day comments.

"Happy Birthday Nelson Mandela" was a worldwide trending topic on Twitter for most of the day.

A YouTube video called Mandela Story also imagined the former South African leader's life through social media sites such as Facebook, Twitter, Instagram and Pinterest.

Created by South Africa-based Prezence Digital, the video asks if Mandela would have spent 27 years imprisoned if he had access to the "same technology, social media platforms and global monitoring tools as we do today?"

The Nobel Peace prize laureate spent 27 years in South African prison and further 40 years in politics - first as an activist and leader of the opposition movement, and later as the President of South Africa and international symbol he became for his role in bringing down the South Africa's apartheid regime .

Tell us what Mandela means to you and how you are marking Mandela Day in the comments box below.