The version of iMessage that accompanies Mountain Lion has several facilities with which to send smileys. Just tested it. If I send a smiley from my 4S to iMessage on my iMac, the smiley appears on the iMac. But if I send a smiley from the iMac iMessage to my 4S, I get "ascii" characters, not the smileys. Is there a setting I forgot to set or mis-set on the iPhone?