I just saw this today. It's called the Sling Sleeve - to get your slings under control when you are storing them. Have any of you all tried it? Here's a link to their page:
Sling Sleeve
Sling Sleeves will hold your sling taunt and snag-free to prevent any serious potential snag hazards created by stowing a gun with a firearm sling attached to it.
www.blueforcegear.com