The smilies to the right can be inserted directly into your messages by clicking on them: :rasta: imp: :thumbsup:

The smiles below differ based on your post. In general, they will display next to your subject. If you are creating a thread, then they will also be visible on the left hand side during thread view. If you're replying to a message, then they will display in your subject line.

For example, there should be a grinny smilie next to my title. But you can't see it from the thread page because I am not the thread creator.