Does this help?
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1225239439/13#13
It's very general; draws line based on a function that draws a point, but at least it's fully fleshed out with all the possible quadrants and directions that it's possible to draw a line in (which is better than most Bresenham examples on the net.) (I didn't write it; I found it!)