I'd be surpised if someone else hasn't already done this, but here goes.
I wanted a bishop bag for my hammock and suspension because 1)it looks cool and 2) it sounds cool. I just knew I could figure something out with the dozens of empty stuff sacks I had around. Mind you...I am not the least but handy around the house, don't sew, and my usual idea of DIY is calling my brother 'myself.'
And there it was. The stuff sack that I bought with my ThermaRest a few years back. If you've ever owned a ThermaRest and the accompanying sack, you know how useless that sack is; once that pad comes out the first time, it's never going back in!
The great thing about that sack, though, is the 'handle' at the end. It's really a deep pocket sewn onto the outside south end of the sack. I picked up a cheapo grommet kit, punched one into the end beneath that handle flap, fed one whoopie through, and oila! The handle/pocket has plenty of room for that end's suspension and webbing, too, and keeps it all nice and tucked away, ready for rapid deployment. Thought I'd post in case someone else out there might want to get or make a bishop bag; I think the ThermaRest stuff sack goes for $15 or so.
Sadly, however, the grommet came off a few weeks later. I assume silnylon requires some sort of reinforcement for a metal grommet like that but, like I said, total DIY noob here. Thought I'd try duct tape, but nothing really sticks to silnylon, does it? The hole hasn't ripped wide or anything, so for now the makeshift bishop bag is performing flawlessly. I'm unsure of the official manufacturer's size of the bag, but it was for a full length self inflatable pad (that, of course, will never be used again ). It is large enough and sturdy enough to hold my ENO double, MacCat Deluxe w/guylines and figure 9s, stakes, suspension, a pair of 6' tree huggers, and a couple of mini s-biners.
Images show size comparison with a standard nalgene and the end handle pocket. Webbing, whoopie, toggle all fit in there and hide away; I pulled them out a bit just for the photo.