Sort Icon for UIToolbar

Does anyone know of a good icon that would indicate to a User that a UITableView can be sorted? I'm l开发者_开发问答ooking for an icon to put in a UIToolbar, aside from putting a button with "Sort" for the title. Any ideas would be greatly appreciated.

The edit button (UIBarButtonSystemItemEdit) is a widely accepted item to indicate that you can edit a table view.

You could use a UISegmentedControl in a UIToolbar or UINavigtionBar for sorting like Apple does on the Recents screen of the Phone application.