Silicon Valley in California is still the world's centre of technological innovation, with a culture of risk-taking billionaires betting on the next big thing.
The Middle East and North Africa is not a region known for its high-tech entrepreneurs, but one spin-off from the Arab Spring is an explosion of online social networking and use of smartphones.
Alastair Leithead joined a group of the Middle East's brightest young entrepreneurs on a tour of Silicon Valley - to announce their arrival in the market, search for investors and work on the perfect business pitch.