Michael is always a tough act to follow... and his great post yesterday on "Ever Been in a Real Fight?" is no exception.
Basically, my answer to this question is "No" if "real fight" is defined as fisticuffs, knives, guns, etc. If you are talking about throwing things around and screaming angrily, then the answer is "Yes." But I can't claim anything out of the ordinary sibling squabbles.
For fiction, then, I have to dig around for resources when I'm faced with creating a real fight with real weapons (or real fisticuffs). I'm always on the lookout for 19th century weapon and fighting resources. For instance, in my ongoing draft I was looking for a small knife a woman from Europe might carry for self-defense. I stumbled across the navaja, which is an Andalusian folding knife and from thence to the salvavirgo (or salve virgo ... the spelling seems to vary), or "chastity knife."
I think not.