By Mark Savage
BBC News entertainment reporter
As the publication of the seventh - and final - Harry Potter book approaches, speculation amongst fans has reached fever-pitch.
Podcasts can be played on a PC or downloaded to an MP3 player
Will Harry die? Where do Snape's loyalties really lie? And will Ron and Hermione get it together in Hogwarts' Great Hall?
For many devotees, the only way to keep up-to-date with the latest Potter news is to download and listen to podcasts - basically radio shows for your MP3 player.
According to one directory, there are more than 150 such programmes being made around the world.
The most popular, Mugglecast, is listened to by a staggering 55,000 people every week.
With a relaxed atmosphere and chatty hosts, the best Potter podcasts bring to mind a breakfast show with the energy and wit of Chris Moyles - only with wizard rock on the playlist, and every item devoted to Harry Potter.
Among the top-rated is the US-based Pottercast, produced via The Leaky Cauldron fan site, which has recently clocked up its 101st episode.
Host Melissa Anelli admits that, in the beginning "we didn't even know what a podcast was", and says the initial programmes were "a nightmare".
"We had no personality on air," she recalls. "We were recording in my room-mate's house at four in the morning, and it was all sounding terrible.
"Finally, John [Noe, co-presenter] yelled at me and said 'go and have a glass of wine'.
"I did, and the next take was the one we used in the show!"
Andrew Sims, the 18-year-old anchor of Mugglecast, says his team had similar teething troubles.
"The first episodes were very informative, but they weren't entertaining," he says.
"Now we have great chemistry, there's a flow. We've nailed down our personalities."
The plot twists of the last book will be discussed in-depth
"Fans even say they have developed a relationship with us. People say we're like their best Harry Potter friends."
These days, the hosts of Mugglecast and Pottercast are minor celebrities in their own right, signing autographs at premieres and fan conventions.
Both shows are marking the launch of Harry Potter and the Deathly Hallows by hosting a series of live shows across the UK and US this summer.
Up to 500 people turn up to the recordings, something which Anelli admits is a "little crazy".
"The first time, I had a little panic attack. I had to marshal the confidence to go out there."
And is there enough fresh material to fill the shows?
"A lot of people ask us that question," says Sims, "especially people who don't know a lot about the books".
"There's always so much to talk about because Harry Potter is so in depth. When the cover for the new book came out, we discussed that for two-and-a-half weeks!"
While Pottercast and Mugglecast cater for the mainstream fans, there are other, more esoteric, podcasts out there.
Actor Chris Barlow plays several characters in Snapecast's sketches
Snapecast, for example, is an adult-orientated show dedicated to menacing Hogwarts stalwart, potions master Severus Snape.
"He's one of the more enigmatic, complex characters in the series," explains Chris Barlow, one of the show's contributors - and the voice of Snape in various sketches and parodies.
"Even though he's cruel at times, there's a lot of humour as well. If you're tuned in to snarky, sarcastic humour, there's a lot of fun to be had."
Author Tim O'Donnell has also serialised his Potter parody, Harry Putter and the Chamber of Cheesecakes, as a podcast.
Based on a book he wrote with his children as part of a home schooling project, it features the entire family in the voice cast - although O'Donnell says he would "prefer not to have to do the women's voices".
The shows are made using a cheap microphone and free audio recording software.
The staff of Mugglecast and Pottercast host live events
O'Donnell has sourced copyright-free sound effects from the internet, while his son plays the theme tune on his guitar.
But the more popular podcasts have bigger overheads, covering the cost of running websites, phone bills, and travel.
"Ultimately it's about $100 (£50) a month," says Kim Newsome at Spinnerscast. "We have a little fund that comes out of my salary and we get a few donations."
Mugglecast, a much larger concern, relies on advertising to fund its shows.
But it is commitment, not cost, that poses the biggest problem.
"People don't realise how hard it is to work with others," says Newsome, who has produced 42 episodes of Spinnerscast since September 2006.
Kim Newsome is a TV producer when she isn't making Spinnerscast
"Somebody's got to be the leader, and somebody's got to push you through even when you don't want to record.
"A lot of this is just not fun."
The rewards of perseverance include tickets to premieres and book launches, interviews with the stars of the films, and meeting fellow Harry hounds around the world.
"We have people contacting us saying 'I listen to the podcast on the way to school with my 13-year-old and it's the only thing we can talk about together,'" says Newsome.
"If you don't have any friends who talk about Harry Potter, Mugglecast is a great source," agrees Sims.
"And it's a once in a lifetime opportunity for us.
"Who knows the next time we'll have the chance to put on a radio show that will have so many listeners?"