What are some uses for clickers/pollers? I've seen clickers/pollers/etc. used in classrooms for many things, such as evaluation and assessment and agile/contingent teaching. 

What other uses are there for clickers in the classroom? 

To clarify: I'm looking for a list of constructive uses for classroom teaching.
The question basically says, "I have a tool, tell me some uses for it." That's fine, but we could also approach this from the opposite side, and ask why the tool was invented in the first place. It's good to know that a flat-head screwdriver works as a makeshift ice pick, murder weapon, or hair pin, but its original purpose was to put in screws and take them out.

There was an educational innovation that was widely popularized by Harvard physics professor Eric Mazur in a 1996 book, Peer Instruction: A User's Manual. The book is still in print. It describes a particular active-learning technique, but it also contains a handy summary of the evidence that traditional teaching techniques work badly in freshman physics, and that active-learning techniques in general (not just this specific one) work better. The findings have been replicated in fields other than physics [Freeman 2014].

In Mazur's technique, a purely conceptual multiple-choice question is displayed to the students. The purpose is not to find out whether the students understand the topic already. In fact, the technique works best if the questions are carefully chosen based on past experience so that you know that roughly half your students understand well enough to get the right answer, and half don't. After a couple of minutes of silent thought, students are polled. Mazur originally did the polling using pieces of cardboard that the students held up. I currently do it by having them hold up fingers (one for a, two for b, etc.). If there is a total consensus for the right answer, the technique has failed and you move on. If some students get it right and some get it wrong, you have them break up into groups and discuss it. Once they've had 5-10 minutes to discuss it, you poll them again. If they now all give the right answer, then the technique has worked correctly. The purpose of the technique is to get students talking about concepts, in their own words. Regardless of the specific technique used, what the research seems to show is that the crucial thing is to get students to talk about concepts.

Over time, some people started using expensive electronic clickers to do what could just as well have been done using cards or fingers. As more time passed, the expensive electronic clickers became "edutainment" devices, designed to make students feel that sitting through a boring lecture wasn't quite such an unendurable waste of time.

Freeman et al., "Active learning increases student performance in science, engineering, and mathematics," http://www.pnas.org/content/early/2014/05/08/1319030111