Together with my little notebook I carry around in my knapsack a black indelible-ink pen, two ball-point pens, one red and the other blue, and a yellow day-glow highlighter. Actually, I have two black indelible-ink pens, one of which is a spare. When no-one is around, I surround myself with all my gear, but I display at most two pieces of writing equipment at a time if anyone is around. The highlighter rarely sees the light of day. I am embarrassed by my anal ways, I suppose.