This brings up another point, How do you let someone know you're coming up on them? I've been out a couple times, riding along, and all of a sudden I feel someone on my wheel. This had happened the past three or four rides I've taken solo. I'm thinking a mirror might be in my future (have to find a CF one that doubles as a coffee stir'r for the OCP). But how do you announce your presence?

Not that I mind, if I came up on myself i'd draft me.