<div>South Africa celebrates the 100th birth anniversary of Nelson Mandela this week. His birthday on July 18 is marked annually around the world, and the Nelson Mandela Foundation called this year for people to take action and inspire change in Mandela's name.</div>''<div>  </div>''<div>Former US President Barack Obama will set the tone for the celebrations with a speech in Johannesburg on Tuesday.</div>''<div></div>''<div>Mandela, who died in 2013, remains a global icon for his long fight against white-minority rule and for his message of peace and reconciliation.</div>