There is a cool feature of Flight Simulator 2004 that I really like; it's the Terrain Detail option. It enables something on the textures to make them look like they are at a higher resolution.

Detailed Textures on


Detailed textures off

This special effect also adds an impression of speed to the simulator since more little things move on the screen.
I thought it would be cool to add this to the sim :P
First thing I thought of was to resample the textures on the objects, add some sort of computed noise on them, then apply this modified texture back...
Not a good idea ...
A better idea would be to use MultiTexturing capabilities of DirectX9 !
A few lines of code later, the effect was in place and working ... The process is simple, place a transparent noise texture on the objects that would add a general feeling of noisiness on them !

Screenshots : (Click to zoom)

Flight Sim Project, without Detailed Texture Effect

Detailed Texture Effect on (Maybe i put too much noise on this...)

Happy Landings !