Check out this link. Not sure how economical it would be.
http://www.returnofthecaferacers.com/2011/03/air-research-suzuki-gtp-550.html#more
Make sure you hit the link at the bottom of that page as well, looks like fun.
Wow, that is incredibly loud :o Nice bit of fabricating though.
That pulse jet bicycle is just nuts BTW. I don't see a front brake so I guess there is one on the back obscured by the "air box" and exhaust?