I seem to eat left handed and one or two other things as well. I do actually think i should have been left handed, but that's what you get for being raised by nuns (seriously, i went to a nun + one priest run preschool for 3 years where I learnt to speak flemish by listening to the other kids, and was taught to read and write there.) Seeing as left handedness is the devils mark, and seeing as how that place was really quite traditional, it wouldn't be surprising if I'd have been made to write righthandedly.
Anyway. Hence the right handed in some things, but not in others!
I'm about 80% ambidextrous. I can do most everything I do with my right normally, with my left. Only, I'm nowhere near as practiced with my left, since I'm a righty. So, I can eat, brush my teeth/hair, throw, draw, write, bowl, bat, whatever with my left, just like with my right, with about 80% facility, or so. However, I can't play guitar for shit, backwards. That seems to be pretty much a hugely muscle-memory dependant activity. Most skills I learned later in life as a righty seem to be the most affected, but the ones I learned as a kid, like the aforementioned, I seem to be able to do pretty well both ways. When I was a kid, I was completely ambidextrous - I did everything with both hands. To such a degree that I could even hardly remember left from right, oddly enough.
I'm surprised there aren't more of us lefties playing right-handed guitar; I actually feel more comfortable with the more agile hand doing all the fretwork.