I would like to be able to "associate" as many items of one page type to another in the CMS. For example, I have a Person class that has certain properties ie name, email, phone number etc. Then I have a ContactPage class which has things like address, phone number, fax number, etc. However, in the CMS I would like to add as many Person items to the ContactPage. It's easy if I just want one, I have a has_one inside the ContactPage class $has_one = array('ContactPerson' => 'Person') and then create a new DropdownField which is a list of all the Person items. My initial thinking is that you have one dropdown field with a button that says add another and clicking it dynamically inserts another dropdown field using jquery. I don't know if this is the best approach. Has any attempted to do something like this? Is there a simple solution that I'm completely missing? Oh and in the Site tree these 2 items cannot be parent-child. I already have a PersonHolder page where all the Person items go under. Thanks.

So basically what you want to use is rather than a has_one you want the has_many option (or a many_many might be better). Then you have a wide range of fields which allows you to manage has_many / many_many relationships.

Out of the box you can use something like the ManyManyComplexTableField or a CheckboxSetField.

http://doc.silverstripe.org/tutorial:5-dataobject-relationship-management
http://doc.silverstripe.org/checkboxsetfield

A couple of modules also contain nice ways to managing many manys

http://silverstripe.org/multiselectfield-module/
http://silverstripe.org/tag-field-module/