I've been listening to this podcast for a couple weeks now: backpacking light It makes me hope for a time when I'd be in shape enough to backpack. I think my last trip was a 2 day 15 mile trip in the "Wilderness of Rocks" area in the Catalinas in 2001.
Trailcast.org is all about Appalachian Trail through hikers. The ones that take 5 months off to do the whole thing. There are some interesting stories and lore in that one.
I remember as a Boy Scout packing a 45lb pack. The ultralight joke is that a normal packer buys a pack and fills it. An ultralight packer gets together the lightest and fewest articles and buys a pack or makes one that it will fit in. Even the latest packs are cheap because there really isn't much to them. These ultralight guys have the "5lb rule" which is: the pack, the tent, the sleeping bag, the stove and everything that is not consumable (water, fuel, food) must weigh under 5lbs. I think the tent I own weighs 6 or 7 lbs. The total weight they carry is 25lbs. Some use tents, but most use a tarp and 'bivyed' or waterproofed sleeping bag. Some wear hiking skirts! Saves on underwear weight I guess. Also, no super expensive trail stoves. A tuna can and a cut off part of an alluminum soda can are configured with holes and a teaspoon of isopropyl alcohol that will burn for 20 minutes. This is plenty of time to boil 2 cups of water, the usual amount for a dehydrated meal. Some hike at night with LED headlamps. The nylon cone and surgical tube water purifier seems to be all the rage. They don't wear boots to hike in, they wear trail runner shoes.
Alot of these hikers create their own gear. Some end up marketing them. This guy, Bill Fornshell is the true prototype scientist, from packs to hoodies to modified shoes to titanium poop trowels to silk hammocks he's absolutely insane! This photo journal of trying to make a lightweight external pack that doesn't make you sweat is a good example: Sweatless Backpack
For now the day hikes take care of my wanderlust, but there is hope I could lose a few pounds and do stuff like this.
