The icon faces are there for entertainment purposes. The message icons will appear to the left of your message topic/post. The Instant Graemlins you use in the body of your message (i.e <img src="/images/graemlins/cool.gif" alt="" /> <img src="/images/graemlins/frown.gif" alt="" />
<img src="/images/graemlins/confused.gif" alt="" /> ) - just click onto the face that best fits your expression.
Tammy can explain the UBB thing.