Low-cost Low-tech "Clickers" (Score 1)

I have used multi-color 3"x5" cards as "clickers" for years to teach classes. Have a set in with one in each of four colors (red, green, blue, yellow) and give each student a set. You can ask multiple choice, true & false, matching, ect.. questions and have the entire class respond by holding up the card with the color that signifies the answer they think is right. No computers, low cost, and very effective. Clickers are a case of too much technology for too little learning, IMHO.