This thing looks all sorts of insane -- but it's real. It's a one-of-a-kind twin pulsejet Harley Davidson motorcycle built as a custom job for a customer who never paid for it. It was briefly up for sale on eBay, but it looks like we all missed out. Here's a video of the bike in action. Something tells me you might just have a little trouble getting this thing registered had you been the winning bidder, but the sale's been pulled from eBay; either somebody bought it, or eBay's got restrictions on selling bikes with massive freaking flames coming out the back.