It would be awesome to be able to group smart lists together into a folder that drops down in the contact screen (for example, have a smart list folder titled "City" and then when you click on it, it drops down a bunch of smart lists filtered by a specific city tag). There's already a "More" tab that drops down other smart lists, so it would be very helpful to create custom ones to group smart lists together for those who need them categorized by import, city, stage in email marketing, etc.
(Originally titled: Smartlist Folders for Organization)