Multi-select pick list "Combo Box"

Multi-select pick list "Combo Box"

I would like to suggest a new field type (or upgrade to existing type), the combo box. This is a single or multi-select pick list that includes the option to type your own entry into the field via a text field. This could be achieved by appending an "other" option to the field options; once this option is selected a text field would appear that allows you at enter your own option.

This option would then be added to the select list once saved. This means standard users have the ability to add new options to the select fields. Of course you could simply add the "other" as an option to the pick list and multi-select pick list fields.