Following in the path trodden by zombie movies, the "found footage" niche has gone from being an increasingly popular trope to a genre of its very own in the past few years.
The form's popularity is typified by this week's release of Paranormal Activity 4, the latest entry in the efficient and economically fruitful horror series that began only three years ago.
Apart from the found footage angle, the Paranormal Activity series has distinguished itself among other horror franchises by actually managing to get better with each entry. The whole thing may have started in a pretty minor place with the first film - which succeeded on its gimmick alone - but I was impressed by how much the second film built on the first, and then by how great the third film was compared to the first two.
Unfortunately, diminishing returns appear to have finally set in with the fourth entry, which is nevertheless not without genuine scares and unique moments.
The success of the original Paranormal Activity film kickstarted the found footage trend in a way that the more successful Blair Witch Project seemed unable to do in 1999, despite being a bonafide cultural phenomenon. It's telling that the hastily assembled - and shockingly bad - sequel Book of Shadows: Blair Witch 2 chose only to revisit the witchy stuff, and ignore the first film's major point of difference by presenting it within a conventional film narrative.
When The Blair Witch Project was first released, it suffered accusations of plagiarism, with many citing the previous year's The Last Broadcast as a clear influence.
Naysayers with longer memories pointed to the granddaddy of all found footage movies: Ruggero Deodato's notorious Cannibal Holocaust, which was making claims of having discovered "actual footage" way back in 1980, when there was no internet to easily refute the claims' veracity.
The film's grim reputation - and animal slaughter scenes - have prevented my sensitive soul from ever watching it, but you can perceive some of its influence on Blair Witch towards the end of this NSFW trailer. Weird music right?
One film that really helped clear the way for the success of Paranormal Activity and the subsequent found footage boom is also one of my favourites of the genre: 2008's Cloverfield, shepherded by genre maestro JJ Abrams, written by Cabin in the Woods' Drew Goddard and directed by Let Me In's Matt Reeves.
Cloverfield's Godzilla-esque scale ably demonstrated that you can tell a blockbuster-sized story within the found footage genre, and it was arguably the first found footage film to accurately reflect (and capitalise on) the increasing ubiquity of cameras in daily life.
Indeed, you could easily point to the smartphone-driven explosion of recorded footage as one of the major factors in the recent proliferation of found footage movies - it just seems more natural these days to witness events in this manner. In a way that perhaps didn't seem as natural back when Blair Witch was such a hit.
The role played by the 2007 Spanish film Rec (and it's inevitable American remake Quarantine) in the found footage resurgence cannot be overstated, especially considering it was cross-pollinated by the zombie boom.
Rec proved a minor breakout horror hit around the globe, and showed that there's a wide variety of stories waiting to be told in the found footage genre.
Which brings us up to Paranormal Activity, which is listed on IMDb as a 2007 film, but which was released widely around the end of 2009 and the beginning of 2010. It's a pretty one-note film that some audience members struggled to engage with, but those who did fell at the mercy of some extremely effective tension-building.
With its combination of an incredibly low-budget and an extremely high gross, an instant sequel was a no-brainer, and the Paranormal Activity series now occupies the old Saw position of having a new sequel released every October.
As I mentioned earlier, I enjoyed how Paranormal Activity 2 built on the first film, but Paranormal Activity 3 was a real revelation. New-to-the-series writer/directors Henry Joost and Ariel Schulman, who were behind the amazing (and still-underseen) Facebook doco Catfish, proved themselves creative masters of the found footage set-piece and managed to build tension up to excruciating levels.
Joost and Schulman are also behind Paranormal Activity 4, which I found to be a relative disappointment compared to 3, although that may have had something to do with the goon sitting behind me in the theatre who wouldn't shut up.
Although he stopped performing writing and directing duties after the first film, Oren Peli, the man who created the Paranormal Activity series, has proved himself committed to riding the found footage wave with his subsequent projects.
He wrote and produced this year's Chernobyl Diaries, an unsuccessful found footage thriller based around the infamous Russian nuclear plant. He also attempted to pull off the world's first found footage TV show with the ambitious Lost-ish drama The River, which had a short run earlier this year.
Peli's next film, and his first as a director since the original Paranormal Activity, is yet another found footage thriller, this time about aliens. Presumably, at least - it's called Area 51. It was shot a while ago, but has had its release delayed for unspecified reasons. Maybe it's time Peli started to diversify.
One of the biggest found footage hits outside the Paranormal Activity series is 2010's The Last Exorcism, which itself has kicked off a mini-trend of exorcism-centric found footage movies, typified by the likes of The Devil Inside and innumerable straight-to-DVD movies.
There wasn't anything particularly original in The Last Exorcism, but the film still worked for me.
One of the more shameless jumpers on the found footage bandwagon is 2011's Apollo 18, which tried to tell a space mission-gone-awry story in the found footage style, but was met only with widespread derision.
Speaking of failed found footage movies, the people behind 2009's The Fourth Kind probably thought they had an original idea, but the film was wholly overshadowed by the first Paranormal Activity, even though it was about aliens.
Not content to be pigeon-holed as a device solely for scary movies, the found footage style was recently applied with relative success to the sci-fi/superhero genre with Chronicle and the teen-party movie with Project X. I liked the former and hated the latter.
When legendary horror director George A Romero decided to make a fifth zombie movie (following 1968's Night of the Living Dead, 1978's Dawn of the Dead, 1985's Day of the Dead and 2005's Land of the Dead) in 2007, he perhaps realised the most economical way to do it was to employ the found footage style. The resulting film - Diary of the Dead - wasn't very widely seen, but apparently did enough business to warrant a sixth film: 2009's Survival of the Dead.
A film whose existence perhaps demonstrates that the found footage movie is at a tipping point is V/H/S, which screened at this year's film festival. V/H/S is a horror anthology that presents a variety of short films (from a variety of directors) all presented in the found footage format.
They don't all fully succeed, but there's no shortage of inventive ideas and the found footage wrap-around story is awesome. Look out for V/H/S on DVD soon (ahem) - its one of the more exciting recent examples of the found footage genre.
Another aspect of the trend is films like District 9, which used found footage elements to locate the viewer firmly on the ground at the beginning of the story before seamlessly switching over to more traditional filmmaking techniques. Not all films do it as well as District 9, but it's clear that found footage can now be accessed as one of many storytelling devices.
Found footage apparently plays a large role in the upcoming horror film Sinister, but in a "film within a film" context. i.e. It's a traditional movie about a writer (Ethan Hawke) who discovers some mysterious home movies. That could work. Sinister opened this past weekend in America to decent business, and is currently scheduled for release in New Zealand early next year.
* Are you a fan of found footage movies? Which are your favourites? Have I missed out any notable examples? Do you think the genre has run its course? Comment below!
Twitter.By Dominic Corry @DominicCorry