The world's news makers will be interviewed with Sir David's incisive style.
Sir David will get behind the headlines and examine the decisions and policies which shape global politics today.
|Jacob Zuma joins Sir David to discuss|
Zimbabwe's ongoing political crisis
Jacob Zuma became the president of the African National Congress (ANC) last year.
He is now the firm favourite to succeed the South African president, Thabo Mbeki, in next year's presidential election.
Zuma is a popular figure in South Africa, despite facing allegations of corruption.
He joined the ANC at the age of 17 despite having no formal schooling.
He was later convicted of conspiring to overthrow South Africa's apartheid government and was imprisoned in the notorious Robben Island prison.
Sir David talks to Zuma about Zimbabwe's ongoing political crisis, and his goals and ambitions if he becomes South Africa's next president.
Zuma tells Sir David that he will carry on regardless of the corruption charges, which he says are politically motivated.
On the situation in Zimbabwe, Zuma thinks the country's electoral commission is to blame for not announcing the results sooner.
He also calls on Zimbabwe's two main political parties – Zanu-PF and the Movement for Democratic Change – to engage in dialogue.Watch the interview with Jacob Zuma on YouTubeWalid Jumblatt
|Walid Jumblatt is the leader of Lebanon's|
Progressive Socialist Party
Lebanon has been beset by violence and political strife since the assassination of former Prime Minister Rafiq al-Hariri in 2005.
The current political deadlock has prevented the election of a new president as the power-struggle between the pro-Western government and the Syrian-backed opposition continues.
Walid Jumblatt is the leader of Lebanon's Progressive Socialist Party (PSP).
He is also a prominent member of the country's Druze community – an offshoot of Shia Islam.
Jumblatt is one Lebanon's most outspoken anti-Syrian politicians and has recently been critical of Hezbollah.
Sir David talks to Jumblatt about Lebanon's current political situation. Jumblatt says that Syrian and Iranian interference in the country is preventing the election of a president.
He also says it would be a big failure for the UN if its inquiry into al-Hariri's assassination failed to identify the culprits.Watch the interview with Walid Jumblatt on YouTubeIsabel Allende
|Isabel Allende is one of South|
America's greatest novelists
Isabel Allende is one of South America's greatest novelists.
Her books have been translated into more than 27 languages and have become bestsellers around the world.
The author is the cousin of former Chilean President Salvador Allende and was forced to flee her country when Augusto Pinochet came to power in the 1970s.
Allende now lives in America where she enjoys joint Chilean and US citizenship.
Her latest book, The Sum of Our Days, reconstructs the painful days following the death of her daughter in 1992.
The memoir is based on Allende's own journals and correspondence with her mother in Chile.
Simon Singh and Jayne Thomas
|Sir David talks to Simon Singh Jayne Thomas|
about homeopathy medicine
In recent decades homeopathy has become one of the fastest growing forms of alternative medicine around the world.
The treatment is based on the belief that natural substances, prepared in a special way and used in minute quantities, can help treat illness.
Alternative medicine is now a huge industry. Europeans spend $800m a year on herbal remedies and in India there are 300,000 registered homeopaths.
The efficacy of these treatments, however, is being questioned. A number of medical trials have found that homeopathy works no better than a placebo.
Sir David talks to Simon Singh, co-author of Trick or Treatment? Alternative Medicine on Trial
, and Jayne Thomas of the Society of Homeopaths.
Singh says that homeopathy does not work and that people with serious medical conditions should see a conventional doctor.
Thomas argues that homeopathy is very effective and has a role to play in the treatment of all diseases and conditions.Watch the interview with Simon Singh and Jayne Thomas on YouTube
|Laura Schwartz says Clinton's negative|
campaign strategy is turning off voters
The protracted Democratic presidential race continued this week with victory for Hillary Clinton in the Pennsylvania primary.
While Clinton still trails Barack Obama in the delegate count, the result makes it increasingly likely that the contest will go all the way to the Democratic Convention in August.
It has been the longest, most expensive and most divisive Democratic primary contest in history.
The party is now seriously concerned that it could be damaging the eventual candidate's chances in November's presidential election.
Meanwhile the Republican Party's nomination, John McCain, has been continuing his campaign to establish his White House credentials.
Laura Schwartz, a former Bill Clinton aide, tells Sir David that Hillary Clinton's victory in Pennsylvania has allowed her to stay in the Democratic contest, but she argues that Clinton's negative campaign strategy is turning off voters and damaging Obama's chances if he wins the Democratic nomination.Watch the interview with Laura Schwartz on YouTube
Frost over the World airs at 18:00GMT every Friday on Al Jazeera English and is repeated during the week.
This episode of Frost over the World aired on Friday, April 25, 2008