Hollywood actor Will Smith and his wife Jada Pinkett Smith have been tapped to host Nelson Mandela's 90th birthday celebrations in London this summer (08). The former president of South Africa is to celebrate his special day with a big charity concert at the capital's Hyde Park on 27 June - and he's called on the Hollywood couple to take charge of the star-studded event, according to British newspaper The Sun. Queen stars Brian May and Roger Taylor, Annie Lennox and British rockers Keane are among the acts who have already signed up for the gig, while U2, the Spice Girls and Sir Paul MCCartney have also been approached to take part in the celebrations. The Spice Girls recently offered to reunite for a final one-off performance especially for Mandela, with Ginger Spice Geri Halliwell saying: "He's just an example of strength and humility and if we could be part of that, celebrating his life - wow."