Portability is a weird problem for a lot of Google Cardboard kits. They're small and light enough to toss into a bag, but the versions made of actual cardboard are a little on the fragile side and most don't collapse down all that thin. Speck, the folks behind those brightly colored CandyShell cases so many people love, have decided what Cardboard users need is a collapsible plastic version of Google Cardboard that can fit in your pocket alongside your CandyShell-wrapped phone.
It's called Pocket VR, and if you're using a Galaxy S6 and want a case on your phone there's a good chance this could be the Cardboard rig for you.
Pocket VR is essentially three pieces of plastic and an elastic band, designed to either hold your phone or collapse down into something pocketable. When you want to use Pocket VR, you unfold the plastic sides and wedge your phone in between the plastic sides. Opening Pocket VR exposes the lenses, and the elastic band ensures your phone doesn't slide out.
Like other foldable Cardboard viewer designs, Pocket VR is missing the button mechanism you use to interact with the screen and there's not top or bottom to the design. This means Pocket VR is strictly a viewer and not really for any of the VR games that have come out so far, and won't work quite as well outdoors as the more traditional Cardboard setups.
Speck is including Pocket VR with their CandyShell cases in Spring 2016, starting first with the the Galaxy S6 for $69.95. That's $30 more than their CandyShell Grip case alone, so you're paying quite a bit more for the ability to be significantly more portable with a feature incomplete version of Google Cardboard. It's unlikely to be something that appeals to everyone, but for those looking to share VR with everyone it's a compelling alternative to the clumsy cardboard boxes so frequently associated with Google's VR initiative.