Another very good crime deterent and the simplest is lighting. I like the chewed up dog's bowl with the "BAD DOG" sign idea.
This movie character dog catcher used to get chewed up alot apparently. It gets good around 43 seconds. Lol! http://www.youtube.com/watch?v=7BXJpmTRSW4
There is a shotgun round that I favor. It's a bean bag and it is supposed to send a shock wave through the body that breaks every bone... I'd rather shoot somebody with that and have them alive to answer questions and explain things to me than just dead on the spot, besides there's no blood to screw up carpets and walls or traumatize family members.. I prefer pepper spray for hand to hand situations for the same reason, there is not permanent damage and after you spray somebody you own them, you can kick their ribs in or whatever you want and they can answer questions when the spray wears off...
Since we're now talking about dogs, this one with the dogcatcher is a good one. http://www.youtube.com/watch?v=UA1WMhojTkc&NR=1
Kel-tec make some interesting little carbines-no idea of quality etc, but very compact, and you won't blow your bollocks off accidentally picking it up the wrong way. Pointability, controllability-pretty important . Why not a MP-5 (semi-auto) clone? Well, cost is one thing, all depends what's legal. http://www.keltecweapons.com/our-guns/rifles/sub-2000/
A well trained dog is really your best defense. See the ads in Robb Report for a few ideas. These animals fully trained can cost $50k plus but you have a house guard and constantly watching eyes with the ability to kill if threatened. it truly is the ultimate home defense. The dog and a 12 gauge pump shotgun pistol grip behind a locked bedroom door should do the trick. Handguns are stupid as it's very difficult to hit anything even when not stressed out/scared unless you are a true expert. The dog will fight to the death for you, Giving you time to prepare, noise will wake you etc, if the intruder gets past the dog, he won't get past the shotgun blast when he kicks the bedroom door in. Good luck Surf
Funny you said that because I'm supposed to check out a Sig 40 cal later today at the local gun shop.
I can see you know about as much on handguns as you do where the price of gold is going. .40 S&W is an excellent handgun cartridge.