Instead of using intarsia or Fair Isle knitting, I used the cheaters way of doign two-colour knitting: the duplicate stitch. Basically, I knitting the sock in black and then went back and stitched my design on top of the black stitches with grey yarn.
More notes after the jump...
How to do Duplicate Stitch
Using a yarn needle and yarn, insert the needle in the bottom of the stitch you want to cover from back to front. Insert the needle into both 'legs' of the stitch above. Then, go back down into the bottom of the stitch where you started.
See this wikihow article on the duplicate stitch for more details.
"Batman Logo Chart" by Elizabeth Thomas