The guillotine is usually one of the first submission techniques you learn when you get into Brazilian Jiu Jitsu (BJJ), submission grappling or MMA in general. It's considered a basic technique and because of that, everyone hates being caught with it. Nevertheless, everyone from beginners UFC fighters get caught in it. What is a bit rare though is the standing guillotine. Check out this video of a sick, sick, sick, standing guillotine a few year back in the IFL.
Here's MMA and former UFC fighter Nick Diaz with a nice video showing a few ways to set up the stand up guillotine submission technique.