So it turns out that OpenGLES2 does not support the legacy fixed function mode of OpenGL v1.x which includes functions like glMatrixMode and glOrtho. I rely heavily on these functions in Daphne's OpenGL code but it looks like now I have to learn the 3D math behind these functions and implement that stuff in shaders instead. I've always wanted to do this anyway, so this will be a nice excuse.
I spent this morning reading my OpenGL books trying to figure out the matrix stuff, and also refreshing myself on how matrix multiplication works. I also played around with ATI's RenderMonkey program.