Back in March, I had a driver give me kudos for riding so early in the season this year. It seems he was a cyclist too, but not ready to face the cold at the time.
This past Friday, riding in the rain, a driver honked at me (three quick beeps) as he drove past. Since I wasn't in his way at all (I was riding on a MUT parallel to the road) and there were no other cars around, I took it as a compliment for braving the elements.