What a great OP, Carmel, and what a great thread! I like what you guys have to say.
I'd like to think I'm the same person online and in IRL, but I definitely communicate differently, especially in English. I'm always slow, when I speak English. Well, I'm slow in writing too, but nobody will ever notice as long as I don't use IRC...
However, IRL I use a lot of irony, sarcasm, and I can even come off as quite offensive sometimes to some people, until they realize: "Oooh, he's right. I never looked at it that way". I also communicate much less verbally and use my eyes, hands and facial expressions a lot. And there's always music - my ex-wife and her husband often just hand me a guitar when they want to know what I think about a certain topic - even in times when my fingers are just useless claws.
Some friends have developed that habit too.
A short story about the efficacy of my methods of verbal communication, that I thought I had long forgotten: At one of my gigs, between two sets, I had an interesting conversation with a woman and we both found an ironic comment I had made very funny. Long story short: that comment ended up in at least 3 different newspapers,
not without my full name and picture, but of course without the relevant context.
Talk to me about spotting reporters
Ahem, OK, back to topic:
Well, online I'm a lot more talkative, simply because the other ways of communication aren't that useful here. I'm also a little friendlier and a little more careful with what I say, because I know it might and probably will be archived for the centuries to come; only to bite me in the a$$ somewhere further down the road of life.