Great point PC.
Honestly there have been probably hundreds of times where I had a super long post all typed up and ready to go. As my mouse moved down to the bottom left of the screen I quickly thought, "Is this post really going to help anybody, or am I just trying to improve my own ego and even worse, maybe hurt some feelings?"
While I'm glad I've been able to catch myself a lot of times and close the window before hitting send, I'm definitely not perfect and have (and will continue) to make mistakes.
My brother has gotten really good at this. When he's going to send a pretty heated email to employees, co-workers, or executives he forces himself to wait and "sleep on it" and even have his wife read the email to get another point of view on how others might interpret the email. He often doesn't send them, or at least makes lots of changes.
One interesting bit: I've found that I get about the same amount of "satisfaction" writing a post and deleting it as I do from actually posting it. Kinda weird, but it seems to happen like that for me... I guess to get it out of my system.