Well, did my good deed for the day (week? month?). Went out to get the mail and in the driveway a couple doors down was a car with its parking/tail lights on. Knew an older couple lived down there so I went over (took my keychain with the mace, of course, just in case the old guy was some devious psychopath) and let them know. I'm not sure how much English the old guy speaks but he understood 'car' at least.
So, I saved someone a dead battery in the morning. Go me.