Going totally tubular.
Did you ever go to a music festival, and wake up in garbage?
I mean, like, surrounded by it? Like, as far as you can see?
So think about that, and then think about this too, OK? When you're out backpacking sometime, just look.
So you're there on the ground, right at eye level with it, and what is out there? Garbagy stuff, mostly.
What fell off trees, and twigs, and leaves, and random pieces of nameless whatever covering the ground, what is it?
Garbage. Tree boogers. Forest hair in the brush.
None of it won't clean itself up.
So what do you do at a music festival - you leave, right? You go home and don't mess with it. You leave the garbage for someone else, but what if that's you? Then what?
See, someone has to, so the folks at Glad (The Glad Products Company) are all smiles, because they invented disposable trashbag tents. For rock festivals and stuff. So if you're the dude (or dudette) which has to do the cleaning, and everybody's crashing in Glad ForceFlex Trash Bag Tube-Tents, then you have a field full of trash bags to chuck stuff into after the premises are evacuated.
And this will work when backpacking too, 'cause there's lots of trash out there, as was noted. You can continue leaving everything as-is and walking away, or, if you want to, with your trash bag tent, which wouldn't be that hard to make, you can do some policing of the area during said exit.
Cool.
Now, what's next? I vote for an edible sleeping pad.
Most of the inflatable ones have some kind of rubbery foam inside, so why not sponge cake? And the shell could be like a fruit leather, you know - flexible but tough. And tasty. I like grape, or apple cinnamon.
This would be the ultimate in multiple use and gradual weight reduction since you eat it up as you get used to sleeping on the ground, and your pack weight drops accordingly, day by day.
And what about bug netting? Toilet paper works, it is breathable.
Hang it over the tent's open end to keep out the bugs, and there it is in your face the next morning when you need it the most. Handy, right?
Speaking of screening, you probably have an old backpacking stove that hasn't been used in years sitting in a corner of the garage, and the white gas in it is all gelled. At this point you think "Toss or not?" Sure thing on the stove, it's toast, but you can still use the fuel, which is good for two different things.
See how we're all multiple use today?
Take this old gummy gelled fuel and rub it on any exposed skin areas you may have. There's a little-known fact here, that this stuff makes great sunscreen. True. Then when you get to lunch, scrape it off again, plunk that residue in your little alcohol stove, and cook. A reasonable amount of hair or peeled skin in it won't hurt - the smoke makes skeeters back way off, though it does attract some flies, and the occasional grizzly. It's like Sterno with a fur coat. (The fuel, not the bears. Bears are like fur coats with an appetite.)
Now, upping it a notch, some people use quilts instead of sleeping bags, but this is still single use, right? And wrapping up in either one to keep warm in camp is still kinda single use, so what can you do with a sleeping bag (or quilt) that's rad?
This one is easy, so easy, for everybody that's done a lot of seam sealing, and has all these half-squeezed tubes of the stuff - just dilute it and paint it on your sleeping bag (or quilt). Make sure you have enough before you start, so as to cover it all.
So when this is now dry, glue on a valve from an old air mattress and you have a sleeping-bag (or quilt) pack raft. It still works to sleep in, and now it's also got a vapor barrier, so it's warmer too, and when you get to a lake or a river you don't have to hike around any longer. Instead, you inflate your bag (or quilt) do some paddling, and if that makes you tired, you've already got everything out, so you can go right to sleep. Repels rain too.
No ideas yet on a second use for a pack. So far it's just a hole with some dead things at the bottom, where it's all dark, but maybe an idea will come along.
More:
Disposable Trashbag Tents Are the Cleverest Way To Keep Camping Clean