wp-monalisa is the plugin that smiles at you like monalisa does. place the smilies of your choice in posts, pages or comments.
, keeping the directory structure intact (i.e.wp-monalisa.php
should end up inwp-content/plugins/wp-monalisa/`).
Update: If you update from a former version please do not forget to deactivate and actiate the plugin once, since database changes will only take effect on activation. You settings will not be deleted during deactivation.