You can also do favorite food, pet, flavor of icecream and fovorite toy. You can use anything that a kid would find impossible for you to know, the more possibilities of choice the more impossible it seems for you to predict.
nice ideas, so you're thinking that kids would be capable to understand the principals of what's really happening? ,(that is, i predict and then the prediction and thoughts match) I'm not sure if a 5 to 8 year old would get this and might be bored by the effect. thanks for your help