Tim,
When I lived in Tacoma, we got one of those door jams that fit under the door handle. It'll definitely slow someone down. One thing that concerned me was your question about "identify yourself" or "freeze." Remember the 4 rules of gun safety.
1. Your gun is loaded, always (even when you take the ammunition out
).
2. Never point your weapon at anything you aren't will to destroy.
3. Keep your finger out of the trigger until you are on target.
4. POSITIVELY IDENTIFY YOUR TARGET AND KNOW WHAT IS BEHIND IT!!!
In any home situation that means a flashlight. I have both a sure-fire and a mag-light, but there are multiple brands that do as well. I prefer a push button in the butt cap, so it's always where it belongs, no matter how I pick up the light.
A motion alarm in the hall leading to your bedroom, should do the trick. You can set it when you go to bed, and at least protect the bedroom, at little cost. Plus you can take it with you when you leave or travel. For less than ten bucks, you can sleep peacefully. Who cares if they take the TV/VCR or the toaster? Come to the bedroom, and they're in trouble.
"Jim Grover," the Personal Security editor from Guns and Ammo, gave some good advice if you do think there is an intruder in your home. Announce, "your in my home, I've called the police, I have a gun." He related this should more than fulfill the "reasonable man test." If they keep coming, they're stupid. (Maybe they can win a Darwin Award?) If it's your girlfriend, she'll certainly let you know.
Besides the Alarm has less hair than a dog.
Chuck