Both speaking and writing have power to effect our thought. By the way, speaking is much better because we can understand if it's serious or just a joke by either voice tone or gesture.

For writing, it's difficult to guess what they're thinking. It's ok to chat by instant messanger, e.g. MSN, Skype, AIM, and so on. the reason for using this is you can tell the other immediately: "I'm kidding" or most of Thais will type "555+" (Ha-Ha-Ha ).

Let's see the blogs and microblogs, sometimes people added 555+ after their comments, but what we perceive depends on our individual moods. For example,

"I'll wait for Toefl score before choosing a University, but I mightn't attend in the same place as you hahaha "

The sentence above is my friend's comment on my hi5. I read this comment around 11.15 pm.  What I thought was negative. Actually, it's just a normal and polite (?) sentence. the phrase "I mightn't attend in the same place as you" has effected to my thought.  I felt like she commented on mine with disgust.

Today, when I read it again, I realize that was just a usual comment.