Where Do You Get Your Characters?

Where do characters come from? Yes, I know they're all basically us in disguise but given that I've never had a beard or a wooden leg I don't know how I managed that particular stretch.
People who don't write like to think they are the fodder for their author friends' characters. I've often heard this said on writers' boards. Someone's best friend was so mortified by being characterised in their book they wouldn't speak to the author for months. But it wasn't her, she cried. I wasn't even thinking of her when I wrote it.
I'm no expert on this but I think the process is usually unconscious. In my last WIP - the one I just revised - a new character appeared to me last Spring. I didn't even invite him, he was just there, fully formed with a name, a life story, even a voice. I could even name the actor who could best portray him in the screen adaptation.
Now if you've ever looked at any of the Novel Writing Software out there you'll know that doesn't happen. Characters need to be outlined to within an inch of their paper existences. Every biographical detail needs to be settled before they can even start to spring off the page. But I hadn't settled anything. He was just there. And I felt I knew him as well as anyone.
So what does that mean? I think we absorb the attributes of the people we encounter. Everyone you've ever put a name to; family, friends, celebrities, teachers, bosses, friends of friends ...you get the picture. Millions of people in a lifetime, all melted down into a soup of humanity in our subconscious. And what we do as writers is form a real live character from that soup, or is it more like clay? I'm getting muddled in my own analogy now...
Anyway, that's why our characters are never any one person in our lives - they have to be an original creation or we'd be hamstrung trying to recreate something that already exists. Our friends and family might like to think they've been immortalised in our writing, but perhaps that's just vanity?

Where do you get YOUR characters?