One off-the-wall choice might be the Mountainsmith Slingback chair. It's a weird little piece of nylon (5oz.) that uses your trekking poles for a frame. I have one, and have had a little success with it. It's definitely comfortable, and it has a little pocket you can stick a sit pad (like the Thermarest seat) into. There are two problems: it tends to collapse when you're not sitting in it (but isn't a real nuisance to set back up), and under the right conditions you could end up sitting in the mud if you stretch your legs out, since it only extends to mid-thigh. (of course, you have the same problem with other pad chair kits that don't have the "lounger" extension; you could always sew a piece of nylon onto the Slingback. On the plus side, it folds up into a bundle about the size of a folded T-shirt, and is very easy to deploy at breaks during the day.

Not sure it's what you're looking for, but it does fit nicely into the "rabbit hole" department.