Sourcerer! now also has an Editor Button:
http://joomlacode.org/gf/project/sourcerer/frs/
So when you press the button, this will appear in your text:
{source}{/source}
If the option is enabled in the Editor Button Plugin, you can also have some example code put into it. So then this will appear in your text:
{source}
[[script language="javascript" type="text/javascript"]]
// Place your JavaScript in here
[[/script]]
[[?php
// Place your PHP code in here
?]]
{/source}
The button for the editor of the Sourcerer! Module will output an extra:
{module module_id_or_name}
If you change the Sourcerer! syntax tags in the Sourcerer! plugin, these will of course be placed in the text instead of the default {source} and {/source}.