Two words: digital watch. Some beep on the hour, others you can set the interval it beeps. [dorky]If you can only find ones that work on the hour, set them thirty minutes apart. n_____n [/dorky]

And then you can use the watch itself as a reality check! Double check the numbers, that is. Also, if you keep it near you while you sleep, then if by chance you hear the beep in a dream, you will reality check and become lucid!

When I first learned how to induce lucid dreams, my teacher said that using a digital watch was the best method. =O