Is it really possible? i have seen lots of my friends sending me big emoticons via facebook chat messages. How they do this??
Yes it is possible. go to http://apps.facebook.com/big-emo-creator , select an image and wait few seconds till the app process your image and give you the code.
But these emoticons are not much useful as you have to remember a huge code to use this emos. However you can give it a try.