I am writing up a game that is size sensitive. It needs to be pixel perfect. I believe the resolution is 480x320 pixels with the iphone being twice the width and height. My code is grid based with images exactly 16x16pixels. I found samples of opengl in the past but I never found any good tutorial that had 0,0 the top left and was the correct size in resolution (which made images look terrible)

What can I use? I'd like to write the code in C# (or C++ but C# is preferred) and use monotouch. I don't know any libraries for 2d graphics. I'll figure out sound and such afterwards and I seen documentation on monotouch for input.