Clients have requested the ability to make a non-selectable separator (horizontal line) in the options for a List field. This could also be useful in a Status field. Just a visual cue to help separate different types of choices in the list. Of course you can do this now in a List field, but the separator would be selectable, which is not ideal.
Click 'Me Too!' to vote up this feature, and add any additional thoughts or use cases in the comments.