From what I have observed, I would say one of the largest single reasons for this type of arts growth is the internet. The relative ease in which to capture and publish this art to a media savvy youth has made superstars out of people like Banksy.
Keep your eyes peeled when you are out you may discover the next big thing, it may be you??
|Eye bombing, creating caricatures from pretty much everything. Image from eyebombing.com.|
|Brazilian street art, creating ad-hoc exhibitions using graffiti and street furniture.|
|LED Throwies, 1xlithium battery, 1 x 10mm diffused LED and a rare-earth magnet, work it out.Image from Instructables.com.|
|A classic Banksy stencil.|
|Pixel art, image from Gothamist.|
|Little people instillation, using miniatures of people in street settings. image from little-people.blogspot.|