I made this a couple of weeks ago, and I'm planing a revised version 2. I've made all the pieces in this 5yards to SUL series in the space of about a month. Before I started I'd never used a sewing machine, now i've become obsessed. Thank you Jay, and all the commenters here who've got me excited about this stuff.
Here's a couple of pictures of the finished pack. I have documented the whole process in far too much detail here:
A couple of mods I made:
Elastic straps on each side to hold a wet tent, anorak, etc.
Elastic straps on the back panel (straight across at the top and in a V shape at the bottom) to hold a sleeping mat or just a piece of foam to give it some back support.
For version 2, I'm thinking of switching these to elastane/lycra/spandex panels, which I think is what Gossamer Gear use on their packs (I've only seen them in videos). I'm also looking for some kind of knitted mesh I can use for a large pockets across the front to hold wet gear, snacks, etc. And maybe a hip belt too.