It's the end of term and summer is here, so what advice would Evan Davis's successful business guests give to youngsters just leaving school now? Entrepreneur James Dyson took five years to develop the bagless vacuum cleaner, Martha Lane Fox went on a 'crazy journey' to set up lastminute.com, and Adrian Ringrose still isn't sure he has grown up, even though he is chief executive of a company with 50,000 employees. Evan asks them all about creativity in business and how important it is.