@evildictaitor: I don't think compiling c# to native would take away the some of the parts of the GC. I have been using mono touch for some time and as I understand it mono compiles the c# down to native code IOS code before it gets loaded on the device. So i think it would be possible to do this.
It is of course perfectly possible to compile C# to machine code and run it without a JIT. It is not possible to run it without a GC.