I have a question about all this. I'm about to purchase some random source game to acquire the source SDK, but I noticed that there are three different SDK's. Does it matter as to which one I use, and if so / or not, which is the cheapest game at the moment taht would contain the SDK necessary to utilize this information. True, I've got other things going, but this could/will help me get a LOT more going in this game/website.