To Use Clickers or Not to Use Clickers
Many people think of classroom voting as being synonymous with clickers, but in fact voting does not have to be conducted electronically. Many faculty have students vote without clickers, either because they do not have clickers available, or because the faculty member prefers clicker-less voting. Clicker-less voting can be conducted by a simple show of hands, with colored index cards (red = a, blue = b, etc.), or by having students hold fingers in front of their chests to indicate the option number for which they are voting. Further, a recent study in physics  suggests that the same results are achieved whether we use electronic clickers or vote with colored cards. For a list of vendors who sell clickers, please see mathquest.carroll.edu/resources.html.
An Argument for Using Clickers – Kelly Cline and Holly Zullo, Carroll College
We have found that clickers improve our voting process. Clickers are easy to use, fun for the students, and the votes are anonymous during the voting process. The anonymity leads to independent voting. Since students do not see other votes, they vote for what they think and are not swayed by seeing most of the class raise their hands for the first answer. We appreciate the fast and accurate data collection, as we keep track of the voting results for further study and use in lesson planning.