I came upon a group of elderly people meandering down a trail once when I was mountain biking, walking 2-3 abreast and looking at the ground. Fortunately I was "pootling" along myself, as we say, and the route was fairly flat. I slowed to a crawl, and politely asked "May I pass on your left, please?" I couldn't imagine being any less polite with that group. Fortunately for them the trail had a pretty good line of sight, or they would've risked being obliterated by someone.

The people who walk in the bike lane on their cell phones on my commute home? Yeah...I pretty much buzz them. If you're going to walk IN THE ROAD please leave the phone in your pocket.