auto expanding list

Hello,
Is there a widget in the Form creator that provides an auto-expanding list?

An example: On a contacts form, I wish to have users provide one or more email addresses, phone numbers, etc. this widget would give a plus sign and allow for the user to enter multiple items (I have attached a screenshot from Google Contacts that provides this functionality).

I know that you can create a faux-subform using a view but until subforms being inside of stateful forms is a reality is there any way to accomplish this in a form?

I tried creating a stateless form but could not figure out how to create a button that resided inside of the form widget area--rather than the designated area for submit/cancel/etc. buttons at the bottom). I also tried an HTML view but got hung up on trying to add an arbitrary button....

Thanks,
Matt