I came up with this my second year of teaching when our class sets of "clickers" were all the rage. I tried clickers once, and found them to be a total pain to plan around, set up, and use. Some people love them. I don't know.
Buy a pack of colored index cards and use a Sharpie to mark the yellow ones A, green B, pink C, and blue D. Arrange them in sets of the four different colors, like so:
When I'm planning to use them for a class, I set them by the door in a basket. The kids learn to grab a set of four cards as they walk in.
1. Quick checks during the lesson. Teach a concept, do an example, and then put up a new example. Make it multiple choice. Then poll the class. I usually do this in two steps: "Get your answer ready" and "3-2-1 hold em up." This sort of prevents the unsure student from waiting to see what everyone else is doing before deciding. Also for some reason, at the beginning, I always get 1 or 2 kids who think they don't have to participate. I just say, while everyone is holding up their cards, "So-and-so, I'm waiting on you..." until he relents and holds up a card.
If the answer was A, you want to see this:
2. Polling for other purposes. Examples: Can you send a text from your phone without any extra charges? Choose A for yes, B for I have a cell phone but texts cost extra, C for I don't normally carry a cell phone. I would only need to accommodate one student in this class:
3. Gauging the confidence level of the class. "How did that last example work out for you? Use the cards like a stoplight. Hold up green for "I'm good", pink for "I'm seriously confused", yellow for "somewhere in between."" This is how this class feels about the first day of the Logic unit:
I hope this is useful. Any questions, let me know!