Time Stamps
Obviously to Rescreatu time.
Ideas on how to implement:
Hover over the message/username
Have it before or after a message
Have the shoutbox announce the time every half hour or so (would also help with advertisers)
Mention
The ability to @ (or mention) a user who is online would be very useful. Something that would alert them (perhaps similar to a found tu alert. Could be turned on and off individually if a user did not want to be pinged.