By Peter Biles
BBC News, Johannesburg
People around the world will be able to send personal greetings to Nelson Mandela by text or email when he marks his 90th birthday on 18 July this year.
Many events are planned to mark Mandela's 90th
A global "birthday wishes campaign" is being launched soon for the former South African president.
The Nelson Mandela Foundation says it is negotiating with mobile phone networks to make this possible.
The online birthday messages will be posted on their website as part of a year-long series of events.
Walking with difficulty and leaning heavily on his stick, the former president attended a news conference in Johannesburg on Wednesday to unveil the extensive programme.
The Nelson Mandela Foundation says celebrations to mark his birthday have already started.
However, 18 July - the day Mr Mandela turns 90 - has been reserved for a private family gathering.
"It's not yet Madiba's birthday, and where we come from, there's a superstition that you shouldn't wish people 'Happy Birthday' before their birthday", said Professor Jakes Gerwel, chairperson of the Nelson Mandela Foundation.
"But we do have important announcements about this year."
Series of events
The focus is on "a celebration of ideas", perpetuating Mr Mandela's ideals of freedom, non-racism and gender equality.
Among the events will be a newspaper series of six interviews to honour Nelson Mandela.
Next week, there will be a reunion of the surviving former defendants from the 1956 Treason Trial and the 1964 Rivonia Trial, which led to Mr Mandela's life imprisonment.
In June, Nelson Mandela's life will be celebrated at a 46664 birthday concert at Hyde Park in London.
Nelson Mandela has allowed his old prison number to be used as a banner in the fight against HIV/Aids.
The concert will come 20 years after the "Free Mandela" concert at London's Wembley Stadium.
In July, Liberian President Ellen Johnson-Sirleaf will deliver the annual Nelson Mandela lecture in Soweto.
Many other events and exhibitions to celebrate "Mandela at 90" are being planned for later in the year.
Nelson Mandela has cut back on his engagements in the last three years, but still finds time to greet many visiting dignitaries and celebrities.