Kay's last paragraph there reminds me of something that effects how I handle things in my own life. It's not "huge" in my life the way the other two pieces of advice I shared are, however, I personally never say something to anyone online or through email that I wouldn't say to their face, nor that would embarrass me or upset me if it was held out for the world to see.
It doesn't happen with me a lot, but when there is a conflict with someone, I have my act together, call it like I see it and get the the bottom if it as efficiently as possible. Once someone threatened to show others what I said to them and I couldn't help but encourage them to do so, since I thought others would see the truth and humor in what I did say. Another time, someone had a meritless threat about legal action and I think got the point in short order that if they really wanted to pursue something with me, they'd have to find something they had a legitimate basis for (basically, they'd better have their ducks in a row and they'd better be right). It can be interesting to see how fast a person gets reasonable when you are confident in how you have conducted yourself. I don't understand why some people tuck their tails when confronted when they've not done anything wrong.
If you only say things you believe in, and feel right about, it keeps things simple and truthful. That doesn't mean being a "yes" person or being fake-sweet, though. Sometimes it's absolutely correct to say something not everyone wants to hear. Just be yourself and don't be afraid to stand up for yourself. But when you do, do it reasonably. Online, in email, on the phone, in person -- I am just me. Like it or not. I sincerely don't want to think as hard as I'd have to in order to have an online me and a real life me