My first time I went for a ride on the Korean subway I was surprised to see tons of young people with bowed heads and madly moving thumbs teeeextting away.

It's a huge part of the culture, but unfortunately learning how to read Korean text messages (문자) is not a standard part of Korean language class.

Some things that I eventually learned:

1. Laughing...
ㅋ ㅋ = kekekeke, cute laugh
ㅎㅎ = hahahaha

2. Sounds of happiness and complaint
잉 = eeeeeng... whining
음냐 = umnyah.. i want mommy!
냠냠쩝쩝 = yum yum chomp chomp .. this tastes good!

3. Abbreviating
Abbreviation happens a lot, just like in American text messages.. here are a few examples
난 = 나는 (I)
알써 = 알았어 (okay; got it)
이젠 = 이제는 (now)

4. Emoticons
ㅠ.ㅠ = crying face
(^_^) = normal happy face
^^ = happy face abbreviated
^.~ = wink!
-_- = disgusted/bored face
^^;; = sweating face
*^_^* = blushing face!

5. Flexible (wrong) spelling
구 =고 (and)
basically any word that when spoken, sounds different from the way it is actually spelled, might be spelled differently in a text msg

Trying to look up words and expression that didn't exist in the dictionary drove me crazy at first, but once I learned to just read text messages as though someone was speaking aloud to me, I was just fine.

PS~ If you have a prepaid foreigner's "Card Phone" like me you'll be relying on text messages as your major method of communication- very cheap compared to making phone calls!