"Yes Men" is about two best friends who are anti-corporate activists. They fake their identities as they go to conventions, conferences, meetings and so on, acting as members from the World Trade Organization.
What they are able to do is hysterical. They build costumes, create funny looking disguises, and get away with so many things. And the surprising thing is they never get caught, and some of it is illegal which makes it that much funnier. One of the costumes that I found funny was a yellow spandex-like suit with an inappropriate shape that pops out from it. They presented that costume at a college to a bunch of kids while also advertising how Mcdonalds burgers are made, which of course is also a joke.
This is one of the funniest films of it's genre that I have ever watched. I highly recommend you watch it too.
8/10