I have just stumbled on to the work of Rick Morris, in particular his use of the one handed American sign language in his regular classroom.
To paraphrase, Rick gets his students to use the signs for "I" (for I have a question), "A" (For I have an answer), and "C" (for I have a comment), when they their hands. In a small group this lets him prioritise his dialogue with his students and helps with the flow of his lesson. He has added more sign language in his classroom to help with other management issues.
This has to be one of the most useful and practical teaching techniques I have seen in a long time and I'm keen to try it out next time I'm training a group.
How dose this relate to clickers?
One thing that many people forget is the "?" button on many Student/Audience Response Systems. On TurningPoint it silently but visually cues up people who would like to ask a question or make a comment - the teacher/trainer/lecturer at any time can pull up the list and see who is next to ask their question or to comment.
If you use Responseware, those questions can also be written by the participant so that in large groups they don't have to stand up and be heard (embarrassing for some and logistically difficult with AV and large rooms).