Mine are quite simple and old fashioned. I keep a Wenger Swiss Army knife with locking blade on my person 24/7. When I am purposefully in a wilderness area I carry an Ontario Knife Company Pilot Survival knife with a 5" blade. My tin has 5 Exacto blades. When I am flying I carry a Sog Paratool in my flight bag in addition to my tin and Wenger. <br> I have been thinking about carrying a "Heart Attack" plastic defense knife attached to my tin. It could be carried under the nylon string and leather shoelaces that I have lashed around it. It seems like it would make a great improvised spearhead. I havent decided on it yet though. It is really inexpensive, but I dont know if I want the added bulk.