I've recently started volunteering as an Assistant Cub Leader and was persuaded to talk to the kids about camping. Told them about envelope sleeping bags and Mummy sleeping bags then brought ought my waterproof bedroll. explained how it meant I could use it and it would give the same sort of protection as a tent but was just like a sleeping bag when one of the kids looked at me and said 'So....it's like a tentvelope sleeping bag?'. It will forever forward be known as the tentvelope. Absolute genius!! That's one of the things I love about working with kids, the spontaneous moments of sheer utterly random brilliance.