Cell Phones

I have developed a specific "awareness" gesture I use when passing drivers (or pedestrians) who are obviously phone-distracted, and are causing or have caused an issue.

I make the "hang loose" sign with thumb and forefinger extended, hold that up to my mouth/ear (like it's a phone), and rotate it back and forth, calling attention to it.

Most people get it.

Maybe it will catch on.

Not as aggressive as "the finger", plus it's very specific as to what the offense was.