Well, people in Skype do it from time to time. Sometimes, all you have to do is ask if they'll run something and they will. That's pretty much how I work (sometimes, if I'm not already running things). And there's always running it yourself if people don't want to. People will literally suck your dick if your run them through a game. However, there's always the problem of not knowing how to run a game, in which case, you could read the book or have someone teach you. And then there are other sites that focus on getting a group together. So yeah, it's pretty much "Ask the right people".
Hope I helped somewhat.