Yup seems this fellow down in New Zealand is building himself a GPS guided cruise missle. The New Zealand military has apparently allready admitted that it would be very difficult for them to detect and counter it. (DuH! they have no warplanes!)
He is using all off-the-shelf components and expects the total costs to come in at 5 grand for the missle.
So if you need a hobby, consider building a cruise missle.