Simple security pins are easy to make. Buy them in large quantities if you need an assortment for regular rekeying.
These are samples of making security pins with a cordless drill, files or hack saw blades, and extra pins. A Dremel might also work well. I believe a 1/8 inch collet would shring down to the standard .115 lock pin. All five took only about 20 minutes to make.
Original materials before starting.
[img][img]http://i211.photobucket.com/albums/bb277/cookiebear7/100_0511.jpg[/img]
Cutting one pin.
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Same five pins after cutting.
[img][img]http://i211.photobucket.com/albums/bb277/cookiebear7/100_0517.jpg[/img]
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Nothing is foolproof to a talented fool. Wisdom is not just in determining how to do something, but also includes determining whether it should be done at all.