An interesting forum post at 3DSociety.org talks about how best to reduce the "little sand-like jaggies on the surface" of your printed objects. Tim-Gibson writes:
Sometimes you can place your 3D model on the bed in a certain way so as to reduce the stepping on the flattest surface of you model. For instance if you were RPing a basic cube, a cube placed flat and parallel with the printing bed would be produced smoother than one you positioned at an angle with only one corner 'touching' the tray. make sense? kinda like you're going with the grain of the wood. Check with your printer.
Too bad we often need to print more than basic cubes, but a great tip nevertheless.