Japanese NET term Ⅰ

Have you ever seen letter [W] at Japanese blog or spmething site?
It means chortle,laugh,smile...
When we write that in Japanse,（笑）.
[笑] this KANJI means chortle,laugh,smile and read [Warai].
And then,we write only the first letter [W].
I guess that firstly,people want to explain quickly in chat and game.
So,they had choice only one letter.
And then,we use it in blog and something NET place. (It's only casual situation.)

For exsample...
　昨日は自転車でこけた。ｗ
　今日は車にひかれた。ｗｗ

In English...
I toppled over by bicycle yesterday. haha.
I was run over by a car today. ahaha-haha.

Yes,more [w] more funny!!