Thanks for that Ascalon! While it wasn't quite what i was looking for, it was still very helpful. I found the concept of storing the algorithms to make the image instead of the image itself interesting especially since I know the racing game "Fuel" used this same concept to develop their terrain (which happens to be the biggest map on any console; 14,000Km^2). While the game itself was kind of lame, it's interesting how they did the terrain. This video kind of talks about how they did it using procedural generation.

He starts off by comparing othe well known open world games with huge maps. If you'd like to see the bit about Fuel skip to around 1:00.

http://www.youtube.com/watch?v=HhyyUiYQolA