I'm playing around with a cheap sleeping bag, trying to set it up as an underquilt for my NoNet by Mosquito Hammocks. I have a big comforter that works as an underquilt with my Eno Double. I just put a .58 caliber round ball (or a smooth rock) in the corner of the fabric, and tie a line around it for a connector. Eventually, I may sew on some permanent loops. I car camp any more, so a little bulk or weight doesn't bother me.