Carrying in the bathroom is a good idea. It seems to be one of the few places in one's residence that does not allow for a good escape route if you did happen to be without your weapon of choice. With that said, I'm making an effort to carry at all times - even in the bathroom. That is definately one place I would not want to be w/o a gun if I ended up needing one.
Early detection is key. The talk about intrusion alarms is good. I need to get some when I move out of my apartment. My father was in LE and our house was rigged with a good number of devices - most of which I cannot go into detail about b/c he still has them and wouldn't want me sharing them with the world. In all seriousness and for those who want to share - what kind of early detection systems do people have out there?
I think getting a dog would be the perfect answer for early detection. Even just having a little toy tog may just put your residence out of question because of the detection risk associated with breaking into your place.