How can I allow users to duplicate a select field while creating a page from a custom content type? I have one select field (filled with taxonomy terms) in a custom content type. I can't figure out how to allow users to duplicate that select field (select "apples" and then add the select field again -- 2 instances of it now -- and select "oranges") when creating a page with the custom content type.

EDIT: is there perhaps a module that would do this? I've looked at similar kinds of modules like Webform, but none of them seem to be quite what I'm looking for.
If you use CCk, you can just edit your field setting in it's global settings and select illimited value number : 

And you get a button "Add another" :

here I just used a text field for the example but it can be a select or anything else