As requested, here's how to have a custom styles pulldown in the wysiwyg. Please note, this is an advanced hack for users comfortable editing some javascript. This isn't officially supported and we'll automate it in future, but for those who want to it right now, here's how:
CMS Builder uses an open-source wysiwyg editor called "TinyMCE". You can find the javascript code that calls it in this file: [program dir]/lib/wysiwyg.php
Search for "theme_advanced_buttons1". That line specifies which buttons to display. You can find a complete button list here: http://wiki.moxiecode.com/index.php/TinyMCE:Control_reference
Remove the "formatselect, fontsizeselect" buttons and replace with "styleselect". This will use a pulldown of style classes instead of the format and font size pulldowns. Like this:
theme_advanced_buttons1 : "styleselect, bold, (... your buttons here ...), fullscreen",
Then just add the classes you want available to this file: /css/wysiwyg.css
If anyone needs help with this feel free to post here.
UPDATE Jun 18, 2008: Removed old instruction that didn't apply to latest version.
UPDATE Aug 5, 2009: Updated which file to edit (/lib/wysiwyg.php) to match latest version.
Dave Edis - Senior Developer
interactivetools.com