Why can't I move the MouseLook script?

Why can't I move the MouseLook.cs script out of the Standard Assets folder?

If I move it out of the Standard Assets folder, it still works, but it can no longer be found using GetComponent by the other scripts.

I can move it anywhere I want inside the Standard Assets folder and the other scripts always find it with Get Component.

Is it a C# thing? My JavaScript version of the MouseLook script can be moved anywhere with no problems.

Just curious

Answered in the docs: http://unity3d.com/support/documentation/ScriptReference/index.Script_compilation_28Advanced29.html