Back in the dark ages crystal phonograph cartridges had removable needles. By replacing the needle with a mass and putting it on the bed next to a sleeping person one could "see" breathing motion and even the recoil from the heart pumping on a 'scope or strip chart recorder. While clearly not a "tilt" detector, a mass on a piezo element might give you, and those gals in your club, a cheap jiggle detector... Aza D. Oberman -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist