I found this photostream on Flickr called Hell Bent Riders featuring Jason Pullen. I've never seen him, or heard of the crew he's with before but the stunts he pulls are wicked.
Apparently he's been dubbed the 'professional Harley stunt rider'. You can check out his MySpace page here.
He uses two Harleys, an FXR and a Sportster. Frickn' wild stuff. And a spike on the German helmet to boot... or should that read Das Boot.