Harry Potter books have been flying off the shelves of stores and libraries in the US faster than a Quidditch player flying on a broomstick.

If the name Harry Potter and the game Quidditch have passed you by, then you "must have been sleeping," says Jewell Stoddard, who is the head of the children's section at Politics & Prose, a popular independent bookseller in Washington, DC.

Politics & Prose bookstore is expecting a huge turnout for JK Rowling's book signing

Harry Potter and the Sorcerer's Stone, the US title given to the Philosopher's Stone, has been on the New York Times bestseller list for 36 weeks.

The book is now third on the bestseller list, and the second in the series, Harry Potter and the Chamber of Secrets, follows it closely in fourth place.

Harry for the uninitiated

For those of you who have been sleeping, Harry Potter is the creation of JK Rowling, who penned the adventures in Edinburgh coffee shops.

Harry is an orphan who has been sent to live with his obnoxious aunt and uncle, Petunia and Vernon Dursley, and their son Dudley.

Much as in Cinderella, the Dursleys treat their own son Dudley as if he were royalty while treating Harry like hired help.

But one day a letter invites him to attend Hogwarts, an elite training school for wizards and witches.

Thus begin his magical adventures. In addition to meeting supernatural characters, including a centaur and a three-headed guard dog, he plays Quidditch, a game much like football - or soccer as it is called in the US - but played on broomsticks.

'Phenomenon, bordering on a fad'

The third book, Harry Potter and the Prisoner of Azkaban, will go on sale in the US on 8 September, and Politics & Prose has already taken 175 advance orders, Ms Stoddard said.

They have sold more than 1,000 copies of the first two books.

At Saint Albans School for Boys in Washington, parents travelling abroad have bought copies of the books and donated them to the library.

When she would make a lunchtime announcement that a new copy of one of the books was available, "I would have to run back to the library and unlock the door. The boys would literally run from lunch," said Edith Ching, school librarian.

Waiting lists for the books often include half of the school's 250 boys, she added.

She asked boys just entering the school what their favourite book was; more than half chose a Harry Potter book.

"That's never happened before," she said. "Harry Potter is taking over our school."

Ms Stoddard describes the series as a "phenomenon bordering on a fad."

JK Rowling will visit Politics & Prose on October 19 for a book signing, and Ms Stoddard is bracing herself for a huge turnout. She has made a large order of the books to ensure she has enough on hand.

A magical appeal

Harry is loved because 'he is just like us', says librarian Edith Ching

Children in the US as in the UK, are completely enamoured with the world that Ms Rowling has created.

"The children keep wishing that they could play Quidditch," Ms Stoddard said. "They keep talking about trying to find just the right broomstick."

The books have given children the idea that they can share the secret world Harry enters when he goes to Hogwarts.

"My feeling is this is a book for everyone," Mrs Ching said. "Even if you don't like fantasy, you like these books because Harry is just like us."

Just like her students, Harry has to buy school supplies. But instead of pencils and paper, Harry has to buy wands and capes, she said.

He also has fears and trials that children can understand. He has the fears of going to a new school, and after having a wonderful year at the school, he has to return to his odious aunt and uncle for the summer, Mrs Ching added.

Adult appeal

The book has been a hit not only with children but also adults.

Mrs Ching has a father-son reading group, and for most books, about 10 families attend. But when the group discussed one of the first two Harry Potter books, 40 families attended.

"And the parents were as enthusiastic about the book as the boys," she added.

For Ms Stoddard, she recognises plot elements that remind her of books she loves.

"In the new book, there are scenes that remind me of the Hound of the Baskervilles, which is certainly one of my favourite Sherlock Holmes books," Ms Stoddard said.

One of the staff at Politics & Prose is saving the third Harry Potter until she has read all of the adult books she has to read for review in the store newsletter.

She added: "That's going to be her reward. She read the other two so fast."