Home Made Security system

[Stormswift]

Maybe this was posted before but I was looking at various security options for my scooter in addition to everything else I will be doing and stumbled on this website:

http://www.zen22142.zen.co.uk/Circuits/Alarm/sma.html

There are more diagrams and stuff on how to do this. I am not an electrical genius and the only circuit boards I see is inside my computer when I need to replace something. Os if someone knows about this stuff, what do you think?