This one's on my wish list:

http://www.swordsmiths.co.uk/Data/Pages/Scottish_12.htm

It's based on a sgian that was picked up on the battlefield of Culloden after the fight.
I've never had any problem when carrying a sgian dhu, or a dirk for that matter. Only oppressive, tyrannical societies come down hard on free citizens carrying little bitty knives...!