Relation widget that uses a select or radio button interface

- Do you want to request a feature or report a bug?
Feature

- What is the current behavior?
The Relation widget is an autocomplete text box.

- What is the desired behavior?
Maybe it is possible already, but I think it'd be cool to select a related collection through a select element dropdown or radio buttons, with the ability to add a new item with a text box... something like the chosen.js interface maybe? I want to create blog categories and think this would be the best UI.. Maybe I will try to make my own widget if this isn't possible already...