My players used to map pretty much every inch of dungeon. Of course, then we were not so much into using mini's. Now, we use mini's constantly and have a huge, table size battlemat. While encounter rooms get drawn on the battlemat, there is a corner reserved for the engineer in my group to draw a small copy of the dungeon map with marker. Unfortunately, he is a perfectionist and anything resembling a crooked line, or not to scale hallway gets erased and redrawn meticulously, but usually while we do other things, so it doesn't disrupt... usually.
DM