Wiki has some interesting stuff.
I’m similar. I am very strongly right-side oriented (I even have some difficulty listening to the phone with my left ear), except I have always used my left eye to aim a rifle. If I want to look at something with one eye, it’s always the right that closes. As with using my left ear, it seems to take much more mental focus to use my right eye, while using the left is pretty much subconscious.
I’m a righty, but I mouse left-handed. I had an inflammation in my right wrist a few years ago and was forced to reprogram myself. Took about 2 weeks.
Aren’t both twins prenatally in the same chemical environment?
I like the vanishing twin theory of handedness. Link via Wikipedia.
So, as Dwight would say, we lefties have the strength of a grown man plus that of a tiny baby.
My husband and I are both righties and our son was a leftie from the start. As an infant he picked up a spoon with his left hand. Later he did every sport he played left handed, wrote left handed etc… Our daughter, however, was right dominant from the get-go. We never steered them in one direction or the other. My husband’s father and sister are both lefties. No lefties on my side. I think the preference is genetic.
Still looking for the cite but if I recall, handedness is genetic, with emphasis on brain development.
The anecdote I remember is right-handed people have practically identical brain wiring and function. On the other hand (pun intended), not only are left-handed brains wired differently than right-handed brains, but left-handed brains are unique among themselves and share similar (but not identical) traits among other left-handed brains.
Third generation lefty here.
Left-Hand Factoid #1 - Left-hand people are the only ones in their right minds.
Left-Hand Factoid #2 - Everyone is born left-handed. You turn right-handed when you commit your first sin.
Left-Hand Factoid #3 - We may be left-handed … but our jokes are all right.
Same here. Strongly left-handed but with right eye dominant. Only discovered the latter when learning archery… leaving me with the options of either shooting right-handed (which feels uncomfortable and unnatural), or never hitting a god-damn thing. Unsurprisingly I gave up archery.
My mother told me that she’d tried hard when I was little to make sure I used my right hand for picking up toys and the like in the hope that I’d be right handed. Personally I think that if this interference achieved anything at all it was simply to make me slightly less coordinated. 
I also use my mouse in my left hand… but use a right-hand configuration (i.e. a right handed mouse simply moved to the left of the keyboard).
Left handed here with a bad (20/200) left eye. I shoot right handed. Holding a gun in my left hand just feels wrong. I did every thing else left handed until I started working on cars. There are some bolts you just can’t reach with your left hand. I am now pretty much ambidextrous with the exception of writing.
I’m starting to think my daughter might be truly ambidextrous. Her father’s a lefty, and I’m a righty, and I was counting her hand choices while we were drawing this afternoon. Without prompting or handing her a pencil directly, she picked up and drew with it in her left hand 23 times, and her right hand 20 times before I lost count. Darn near even. She’s going to be 4 in February, and as I understand it, most kids have chosen a hand by now.
Even better, she holds a pencil perfectly with that tri-finger grasp in either hand, and has what seems like equal dexterity (sinisterity?)
Someone told me the other day that left handed fathers are linked with dyslexic kids. Anyone know if that’s true? She doesn’t seem dyslexic, in fact the other day she spontaneously showed me how a p becomes a d if you rotate it. But if it’s true, I’ll keep a closer eye on her.
My father is left-handed, as is my elder son. I and my wife are right-handed. So if there’s a genetic component, it’s evidently recessive. (Which makes sense, given the relative frequency of the traits in the human population.)
Interestingly, my father writes right-handed, as he was educated in the era when lefties were forced to switch. However, he swings a baseball bat left-handed–that’s considered an advantage in baseball, so he was encouraged to swing naturally. I learned to bat and golf from him, so I swing lefty as well, despite being right-handed …
If I ever find a second-hand set of left-handed golf clubs for a good price, I swear I’m going to buy them. I’m tired of waiting to inherit his. 
My parents are right-handed but my brother and I are both left-handed. My son is left-handed, but both my brother’s children are right-handed.
I use a mouse with my left hand and have a left-handed mouse. My brother uses the mouse with his right hand, so he can write with his left.
My husband and I are both righties, and both kids are lefties. However, I use a bat or tennis racquet with my left hand and my kids eat with utensils in their hands the right-handed way. I do believe it’s a continuum from “strongly left” to strongly right". of course, YMMV.
Leftie or ambidexterous (I still have times when neither hand feels right for cutlery), forced to write right-handed, but my dominant foot is the left, my dominant eye the left, and when my parents signed me up for tennis I was incapable of using the racket with my right hand. The coach tossed us balls to the right for a forward shot, I’d switch hands and hit a perfect backhand; he then tossed us balls to the left for a backhand, I’d switch and hit a forward. Since he insisted in treating that as “this girl is a stupid stubborn brat,” rather than as “ok, so you’re a leftie for tennis,” I gave up tennis after the third class left me in tears for the third time in as many days.
I think it was Pete Sampras who was an OK tennis player until he broke his right wrist, decided to train leftie while it healed and discovered that hey, he IS a leftie!
Dad was (perhaps) a rightie - he used the camera viewer with his left eye. Mom’s rightie. Middlebro is slightly dislexic and not-quite-a-rightie. Littlebro, rightie. Dad’s all three brothers, lefties. 8 of my 9 cousins on that side, lefties. Both cousins on Mom’s side, righties (the male cousin, more dyslexic than my bro).
I moved the mouse to the left of the keyboard at home to avoid RSI since I moused a lot both at work and at home. Didn’t take long to get used to. Then I got a job where I don’t use a mouse at all*, now I only mouse right handed when trying to beat flash games that require really fast clicking or extreme accuracy.
*I don’t use the computer as much, it’s a laptop, and I’m happy with the built in pointing device.
Interesting. I have the opposite experience. I write and eat with my left hand, yet do almost everthing else with my right hand. Unlike you, though, it didn’t help much that my right-handed parents never considered that I could possibly be left handed. It wasn’t until the first day of first grade (yes, I’m serious!) when the girl sitting next to me (hi Connie, if you’re out there :D) saw me struggling with the pencil in my right hand and showed me how to hold it with my LEFT hand. D’oh.
I do blame all this on my inability to play any sort of sports with any proficiency whatsoever. Hey, it’s a good an excuse as any, and I’m sticking to it.