Bill Gates on giving away his fortune - and Mark Zuckerberg's engagement?

Bill Gates' intimate interview with the Mail on Sunday revealed some entertaining insights about the Microsoft co-founder, who's promoting the Global Alliance for Vaccines and Immunisations conference in London today. We've read it, so you don't have to:

• He's given $28bn to charity and is still worth $56bn.

• His three children will inherit only "a minuscule portion of my wealth" - said it to be $10m each. "It will mean they have to find their own way." (Find their own way... to the bank, as a colleague has just wryly added.)

• When asked if his kids have iPads, iPhones and iPods, Gates replied that they have the Microsoft equivalent. "They are not deprived children."

• He has a Twitter account but struggled with Facebook because of too many friend requests.

• He drove his daughter and her friends to U2's recent gig in Seattle, and then Bono stayed at their house.

• In 1994 Gates bought the Codex Leicester, one of Leonardo da Vinci's notebooks, which cost him $30.8m.

• He nods to speech and voice recognition as "the next big thing". You'll be able to touch that board or speak to it and get your message to colleagues around the world. Screens are cheap."

• He still has a letter from his mother, who died from breast cancer in 1994, in which she says that "from those to whom much is given, much is expected". Of his decision to fund vaccination programmes, rather than developing treatments for cancer, he said: "When you die of malaria aged three it's different from being in your seventies, when you might die of a heart attack or you might die of cancer. And the world is putting massive amounts into cancer, so my wealth would have had a meaningless impact on that."

• Regarding his friendship with Facebook founder Mark Zuckerberg, Gates may have let slip that Zuckerberg has become engaged to his girlfriend of eight years, Priscilla Chan - though Facebook PR has denied this is true. "His fiancée Priscilla thought about education and he gave money to Newark, New Jersey, and we did a co-grant so that some of our people who had some expertise in that field could help him out. He deserves credit. I started meaningful philanthropy in my forties. He's starting way earlier."

• And does he mind being called a 'geek'? "If being a geek means you're willing to take a 400-page book on vaccines and where they work and where they don't, and you go off and study that and you use that to challenge people to learn more, then absolutely. I'm a geek."