It's surprising that that emoticon can be found on that list.
It's not there are a lot of them, it's that they can be made however you want. So there's endless variety in the ones you see. There isn't some set list of Internet-approved emoticons or something.
I think that there is a kind of a thing that you type something in hiragana and it turns up like this. I doubt that they type every dot there.
Over here, teens use smileys pretty much instead of periods and exclamation marks. In real life they're not smiling and laughing with every single sentence they say.
Edited: 2011-05-06, 7:58 am
On the iPhone at least if you have the Japanese keyboard active you can access these emoticons by:
If Roman alphabet is active, select the globe key.
Your keyboard should have hiragana on the buttons.
On the bottom row, second from left (next to the globe icon) there should be a button with "^^" and a dash under those eyes.
By pressing this it should pop up a list near the input field, press the arrow.
You should now be able to see a crapload of these crazy emoticons.
This is one of the longer ones:
Edited: 2011-05-06, 7:59 pm
／人 ◕ ‿‿ ◕ 人＼ わけがわからないよ
Hmmm... Should I start SRSing emoticons now??? :/