JJ Ajax Shoutbox
This shoutbox module allows users to post on your site with a simple yet elegant design. Parameters allow you to choose whether guests are allowed to post, the number of posts shown at any time, the design of the shoutbox itself and much more.
Posts can be easily deleted by any administrator, whilst a spam filter censors swearing on the shoutbox. There is a .php file in the module which you can easily add any extra swear words to if you feel this is needed. The module is entirely language file based, and thus can be adapted for multi-lingual sites easily.