My friend recently baught me a Kensington laptop computer alarm for my moped. It is really interesting and works great on the moped. The way it works is it has a padlock thing as well as a keypad. You may arm it by pressing 1 and 3 simultainiously, once armed any slight movement to the unit (or in my case the moped/unit) will trigger the alarm and make it sound (very loud too). you can disarm the alarm by entering your code into the keypad. It also has a flashing red LED when armed, which would help deter possible theives from taking a chance at the moped. (http://www.macyummies.com/kensonnotal.html - you can look there for a small picture of the unit). I place it behind my dash on my targa lx. Where at night the red led is very visable. A simple but effective idea by me- Wisky.