Without giving too much away, this story explores the concept of the "unexpected superhero", but uses as protagonists three high school kids who are not mature enough or responsible enough to cope with what happens to them. It's a metaphor for the line in "Spiderman"... "With Great Power comes Great Responsibility.
Mutch of it is shot in a Blair-Witch-esque camcorder style which can be more annoying than atmospheric. The leads and story threads are perfectly competent without being stand-out, but perhaps the strongest thing in the movie's favour is the way that it resists the temptation to over-play it's hand. There is something entirely believable about the trials and tribulations of these kids, from the initial childish pranks to the progressively darker second half of the movie.
A fresh approach, competently executed and a good evening's entertainment.
Just one word of caution about the so-called "Digital Copy" offered with this particular format. I run iTunes on Mac OS/X and have the latest iTunes version (10.6.3) Despite my being able to download the digital copy from the web site, I cannot run it via my Mac by virtue of the fact that I'm told that I need a different version of QuickTime to work with this content. AFAIK I'm on the latest copy. I suspect this may be related to the non-standard way of downloading the content, it does not seem to come wholly from iTunes.