At best these conspiracy theories are a poor substitute for real criticisms of the very real problems with global finance and the fractional reserve banking system, and the way that powerful private interests control politics. At worst they degenerate into outright lunacy involving, variously; alien reptiles, the Devil, a mass plan to depopulate the planet (which appears to be going swimmingly), and just about anything else you can imagine.
In all NWO theories there has to be a "them", a group behind everything. However, nobody within the subculture can agree on what the them is, exactly. So you get; The Bilderberg Group, The Vatican, The British (I've seen that and its hilarious), The UN, The Devil (again), Aliens, Alien Lizards (again, David Icke's prefered choice).
Its a small point but I find the idea of them trying to create a one world government amusing. This is the phrase that conspiracy theorists use all the time. I think you mean a one government world. There is of course, only going to be one world.