Kind of like the thinking behind this.

http://www.sierradesigns.com/backcountr ... bed_120413

I love that, its the nicest design I've seen in a long time, although i cant see it being mega warm? :D

Intriguing in a weird kind of way. Is it "backless" so the matt provides ground insulation (like quilts)? I can't tell from the blurb.

Edit:

Available in 2-season (30⁰; 2lbs; $349) or 3-season (15⁰; 2lbs, 7oz; $399) models next year, with regular, long, and women’s specific models.

So quite pricey and not that light by the looks of it

Every now and then someone re invents the bike but in reality nothing is new and is often worse, looks like this has done again with the sleeping bag, .

If it was just big enough for two, it would be brilliant.