Well, finally after my first post here I finished the wordpress plugin version.
SmileTAG is a shoutbox with lot of themes (currently 9 themes available). It uses Ajax for auto refresh, but the main focuses is template flexibility, so you can easily create your own themes for your shoutbox.
I've tested this plugin for WordPress 1.5. If anybody able to use it in other version, then please let me know ;)
You can get smiletag here.
Ok, hope this usefull. Thanks for the support so far. Especially to spencerb ;)