I agree with kevwil on #3. It drives me nuts when I am conversing with someone via IM and wait three minutes for each response. I expect an immediate reply, just as though we were talking face-to-face. Ignoring our conversation to browse, shop iTunes, read, or chat with others is just plain rude. I call people on this all the time. A passive-aggressive “Well, it seems as though you are too busy to chat, so I will talk to you later” comment often works wonders.

While #6 might be good advice for females and minor celebrities, it doesn’t really impact the rest of us, in my experience. Few will bother you online, and even if they do, ending it is a simple “ignore” click away.