The seventh and final Harry Potter book goes on sale in locations around the world at a minute past midnight local time on Saturday (July 21) -- 2301 gmt on Friday (July 20). From London and New York to Mumbai and Australia's Outback, fans are expected to queue at bookshops, hoping to buy one of the first copies. It's a publishing milestone that ends months of fevered speculation among fans over the fate of the fictional boy wizard and his wand-wielding friends. In London, readers young and old are in line with a long wait ahead. Some have been in line for days. Many dressed like their heroes for the grand finale of the Potter saga, which experts believe will be the fastest-selling book of all time. Author J.K. Rowling was an unemployed single mother without a publisher or agent 13 years ago, but is now the world's first dollar billionaire writer after the huge success of her first six novels and the Hollywood movies based on them. "Harry Potter and the Deathly Hallows" will hit the shelves in a carefully orchestrated release designed to maximise suspense and sales internationally. But it has been marred by leaks of the contents of the book on the Internet, both real and fake, and by a mistake made by an online U.S. retailer that meant a small number of hard copies were sent to buyers days ahead of publication. One of the first to queue in London is Martin Meijer from the Netherlands. It's not the first time he's tried to be first to get the latest Harry Potter book. But on the last occasion he joined a line stretching for one and a half miles. He's ignoring all the spoilers and leaks and plans to read the last book in the series as soon as he gets it. Fans in central London feasted their eyes on sealed boxes containing copies of the coveted publication which began arriving at London bookshops mid-day on Friday. Araventhy Nanthanan, a self-confessed Harry Potter fan, says when she gets her hands on a copy she's going to "scream and run around". In New York City in the U.S., a street in the Soho area has been cordoned off and temporarily re-named Harry Potter Place. The area is now a fantasy land complete with replicas of the purple Harry Potter Knight Bus and Whomping Willow. An author-signed copy of the U.S. edition of the book was displayed in a sealed glass covering in Harry Potter Place along with the six other books in the series. Scholastic, the U.S. publishers, held a national Harry Potter essay competition to mark the occasion. The winners will be given free copies of the book the minute it is officially released. The last round of winners was announced at a news conference in Harry Potter Place. "They're going to send us over to a reading room at the Hilton," said Tam Dang, one of the contest winners. "There's going to be pillows and refreshments and we're all just going to sit around and read, I'm excited. I'm excited, I'm not going to lie." While Dang celebrated, the Harry Potter illustrator Mary GrandPré said she felt sadness at the thought the series has come to a close. "Now, as we approach the release of the last book, there's some sadness - it feels like my child is leaving the house and I won't be seeing him again," GrandPré said. Even those who will have to wait for months before translations into other languages appear are joining in "Potter mania." German fans will not be able to read a translation into their native language before October 27. Yet some bookshops are advertising all-night opening hours so fans can buy the English language version, and the country's largest costume store "Der Karnivalswierts," which normally specialises in carnival gear, says Potter costumes are its hottest-selling items. But the big question on everyone's lips is what fate has J.K. Rowling in store for Harry? One German Fan is resigned to the young wizard disappearing from her life. "I think we will have to accept that it is over if the book is brought to a nice close," said Hanna Moles from Cologne.