I know I'm doing something right when I can add a new feature within minutes. I added the ability to archive backlog items to the web-app I'm working on. This is one of my goals, as I want to be able to add and pivot features based on feedback and competitor apps.
To "Unarchive", simply go to search and find archived items and sort by archived date. Nice and easy interface without having to implement a "Archived/Deleted Items" page. I chose "Archive" since items should never really be deleted. In Jira, it's a pain in the but when someone deletes and item and it's no longer available to view.