This will create a customized search page with the vertical checkbox lists (typically used with Home Features and Community Features) broken into two columns instead of one long column.  See the two images included for an example of what this looks like before and after installation.

INSTALL:

**!!**
Important: this was created using code from OR SVN 2.1.6dev Revision 1361.  I doubt it will work on anything earlier.  I'm only working with this version and up, so I will modify it when 2.2.0 is released, but someone else will have to downgrade it to 2.1.5 or below if they can.  I would not install this unless you are working with the SVN version.
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1. Extract the "customsearch" folder containing addon.inc.php and this file and upload it to the /addons folder of your site.  You don't have to upload the two images, they are just to show you how this addon changes the layout.

2. Place the {addon_customsearch_link} wherever you want the custom search form to appear.  Typically, this will replace the {search_fields} tag in the search_page_default.html file of whatever template you are using.

3. Go to Admin > Listing Template Editor > Search Setup and change the Search Type for the Home Features to "Checkbox list of individual values" and tick "Allow Searching".  Do the same for Community Features if you want both to show up on the search form.  The rest of the Search Type setup is up to you, Field Order, etc is used just as before.  Save your setup.  

4. That's it!  There are no admin entires or other options.  When you view the Search Page you should see two (more or less) equal columns of check boxes for those two fields instead of one long column.  


OTHER POSSIBILITIES:

This addon essentially just copies a big chunk of search.inc.php so that the way the search fields are displayed can be customized as needed without messing with the core code.  The way each type of search field is displayed is governed by the different cases under "switch ($searchbox_type)".  After installing, your installation of OR will use those defined in the addon instead of in search.inc.php.  

In this instance, all I have changed is the code under case 'fcheckbox' which controls the multiple checkbox display.  You can experiment with other changes by modifying the others in the same way.

This is my first try at an addon and there may be unintended side effects that I haven't come across.  It's very much "as is" but it seems to work fine for me.  I'm sure others with more knowledge of php and OR can create more customized variations of the search, but this is a start.  Please direct any questions to the forum as I don't really know much more about this than I have already written.

Enjoy!