Communicating in plain text can be really tough; it just doesn't allow the subtlety, nuance and level of emotion that humans need to understand conversations properly. If you struggle with it, the Sound-Word Index might be able to help you out.
Everyone eventually trades up from the AIM app to IM+ or BeeJive or Meebo, but the free AIM app for the iPad actually looks decent.
The Availbot was a neat prototype, but this USB i-Buddy we just saw takes instant message emote representation to the next level. When one of your pre-specified MSN buddies signs on, the little monarch man blinks its lights, flaps its wings or twists its body in a way that can only be described as incredibly spastic.