Shout Box

Yes, it’s possible. I tried it, took a few minutes.

http://www.tom-hanna.net/testblog/?page_id=10

You’ll need a second plugin to allow you to run code in the posts. PHPExec is one plugin that does this:
http://priyadi.net/archives/2005/03/02/wordpress-php-exec-plugin/

Using Jalenack’s WordSpew plugin for the shoutbox –
http://blog.jalenack.com/ajax/ – I didn’t have to adjust the width – it automatically expanded to fit the space. You can edit the file css.php to adjust the size to suit you and other style items.