@Dgold - I don't use the visual editor either. In fact I abhor the thing.
@StrangeAttractor - I modded core files which is something I advise against for 2 reasons:
1. If you don't know what you're doing you can completely f**k your site
2. Your mod will vanish the next time you upgrade.
Having said that the file you're dealing with is located at wp-includes/js/quicktags.js Open quicktags.js and at about Line 60 you'll see...
edButtons[edButtons.length] =
new edButton('ed_block'
,'b-quote'
,'\n\n<blockquote>'
,'</blockquote>\n\n'
,'q'
);
Somewhere below that add...
edButtons[edButtons.length] =
new edButton('ed_pull'
,'p-quote'
,'\n\n<blockquote class="mag">'
,'</blockquote>\n\n'
,''
);
That will add the pullquote button to the toolbar.