One of my most successful homeschooling gadgets this semester was a hot dots pen, along with their accompanying hot and cold dots. Though there are available flashcards and interactive mats that are sold for the pen, we use it for test prep--and my son loves it.
To use, I find or create a multiple-choice worksheet, and place a "hot" dot on the correct answers--and "cold" dots on the others. When my son puts the pen on the correct answer, the pen lights up and tells him, "Correct!" or "Good job!" or some sound of success--and of course the opposite for a wrong answer.
I might use them to jazz up some flashcards next semester, too!