Who says you can't make it big just with game modding? While some game developers frown upon the act of modifying a released game, and even more on the act of releasing said mods, others have embraced the reality of this gaming sub-culture. And others, well, they might even reward you for it. Valve has not only sanctioned the mod that is now officially known as Half-Life 2: Update, it is even allowing it to be distributed on Steam. Provided, of course, you own the original game on Steam as well.