MATES duel with wands in the sky. Maccas drive-thru is broomstick fly-thru. And if you're on your phone while riding your broomstick, you ought to head straight to Azkaban.

No, Harry Potter fans haven't gone nuts in the streets. It's 'public pottering' – a fad like planking, just with a clever Harry Potter twist. That's how the three young Australian men who invented it describe it.

"I think it's a bit more innovative (than planking)," said Martin Kastengren, 21, who began the fad with George Andrianakos, 21 and Simon Carr, 19.

The men, who say they like Harry Potter (but insist they are not the kind of people who are obsessed with J K Rowling's creation), have only been 'pottering' since they posted a few backyard stunts on their private Facebook pages at the beginning of the month. They then started a fan page after university one day.

Many of the photos show people performing complicated gravity-defying stunts. One man mows the lawn with one hand while mounting a broomstick with the other.

Another woman is seen reading a book mid-air. Two men are seen duelling in a Draco Malfoy versus Harry Potter style duel above the Sydney beachside suburb of Bronte.

A photo of one of the men on his broomstick near the beach while on his phone has the caption: "WANTED!!! For flying on the phone. If found please contact Dementors on 1800AZKABAN".

Safety is an issue the creators are aware of, Mr Kastengren said. "We obviously warned all our fans not to harm themselves."

In 2011 Prime Minister Julia Gillard publically urged plankers to consider their safety after a 20-year-old man plunged to his death after performing the act on a seventh-story balcony in Brisbane.