Queen Elizabeth has ordered staff to buy her an iPad - after being wowed by her grandsons' gadgets.Princes Wills and Harry gave her a crash course in how the touchscreen tablets work when they took theirs along to Buckingham Palace.The 85-year-old monarch will be able to browse the internet, watch music, play games and download apps.The iPad costs up to £650. The Queen is a big fan of Apple gadgets and already owns at least two iPods.A royal insider said: "The Queen hadn't seen anything like the iPad before. She was very impressed."She was particularly taken with how easy it was to use, the large screen and how light it was."For a woman of her age, she is very switched on. It was only a matter of time before she asked someone to go and get her one."They added: "The Princes think it is hilarious. They love the fact that their gran wants an iPad and think she's really cool."The Sun revealed in 2005 how she bought a £169 silver model which could hold 1,500 songs. President Barack Obama gave her another iPod when he came to London in 2009. It was loaded with images of her trip to Virginia as part of her official tour of the US two years earlier.The source said: "The Queen has a mobile phone as well as the iPods, so an iPad is the logical progression. She thinks it will be great to keep her entertained on all the long trips she has to make."Apple has sold 20million iPads since the latest version was launched less than two weeks ago.Source: The Sun