The chat application has been made for PDA and uses the ajax scripting language. It could make the page jump up every few seconds. This happens because ajax reloads the chat conversation.
A possibility is group chat, it is some kinda chat box. You can enter a password or name into the group field. If someone else (that you know) enters the same text he / she enters into the same conversation as you are. That way you can have a private chat with people only you know.
You can also use smilies: