There is a whole movement around ultralight backpacking (wikipedia, rei, lolw) which I have gotten into the last few years as a lighter pack does make backpacking more enjoyable for me. Mostly I like it because if I can lighten up standard items then I can bring more luxury items. (Heavy camera / fancy food or drink / chair / whatever works for you) But hiking with less weight is just really nice too.
There were two main ways I went about getting lighter (though the article in wikipedia and rei will discuss much more and in depth)
1) Buy newer gear, that uses better materials and design, for the ‘big three’ (shelter / sleeping / backpack) as well as others. These seem to be slowly becoming available in mainstream gear outfitters, but is really a cottage industry still. Some of the places I have gotten ultra light / light gear are http://www.zpacks.com/ http://borahgear.com/products.html http://gossamergear.com/ https://www.mountainlaureldesigns.com/ https://www.hyperlitemountaingear.com/ You can also find things on massdrop.com which is a group buy site. You have to create a signup in order to see prices as they are often lower than the advertised minimum allowed by the manufacturer. But sometimes the deals are really good so can be a decent way to save money. A plus side to the cottage industry is that people are generally very responsive to email and will be happy to customize things for you.
2) Take less stuff. Don’t take things unless you absolutely need them. Take things with multiple uses. There are endless ideas and discussions about this on the web. http://www.backpackinglight.com/ is a good place to poke around. You have to pay to access articles and post to the forums but you can read the forums for free – and there is endless discussion about everything there. One example: I replaced all the tubes of stuff I bring. Instead of bringing 5oz of sunscreen + the tube I bought some little plastic bottles and put 1oz of sunscreen in there. My general goal is to be almost out of anything ‘consumable’ by the time I get back. I bring some extra just incase there are issues but I don’t need to bring 5 times as much sunscreen as I need. You can also make toothpaste dots that weigh almost nothing for any given trip vs a 3oz travel tube of toothpaste. Seems crazy, but as you do this type of reduction to everything, you suddenly discover you saved 4oz on 8 things and your pack is 2lbs lighter.
Some of the things I have changed in the last few years:
My “Big Three”:
* I have a zpacks arc haul (http://www.zpacks.com/backpacks/arc_haul.shtml) which only weights 24oz for a 60L backpack. Easy to find 60L packs at REI that weigh 3-6lbs (though I have seen a few dropping into the 2-3lb range)
* Sleeping bag is an incredibly warm down bag made by golite (sadly out of business) which weighs in slightly over 2lbs. I have that because I am a very cold sleeper and need lots of warmth. Plenty of lighter bags available. But that replaced a 4+lb bag that was less warm. I use the weight savings on my pad which weighs about 20oz and I love as it is cushy and wonderful.
* Shelter for trips not expecting much rain is a bivy sack from borah gear which weighs 13oz. Doesn’t get much lighter than that.
And for cooking I use a caldera-cone with starlyte stove and titanium pot which is a very light efficient alcohol stove setup. Alcohol has less energy per weight than propane, but the container weights much less because it is just a plastic bottle. (And that stove weights very litte) Someone has handily built an online calculator to work out fuel weights and how long a trip has to be before propane stoves are a better option than alcohol or esbit. (Esbit always wins, the ‘stove’ weighs essentially nothing and the fuel is quite energy dense. Only down side with esbit is you don’t have a way to stop burning the tablet so you need to practice beforehand to know how much to burn to boil X amount of water.
I hike in shoes as they weigh less and I don’t get blisters. I usually use montrail trail running shoes as I can get them at a good price locally but there are lots of options. (In the Bay Area you can get Mountain Hardware gear (and Colombia and montrail) about half off at their Employee store in Richmond)
I also use poles to protect my knees as I have never had great knees. Since you are constantly picking up and putting down the pole when you hike I got extremely light poles (http://gossamergear.com/lt3c-trekking-pole.html) which weigh something like 2-3oz a pole. Compared to, 10-12oz for a ‘standard’ trekking pole – it is very noticeable. Also useful with poles is to watch some videos on proper usage and see how people use them effectively. On thing I heard that stuck with me is that if your arms are not sore the next day you are not using your poles to their full potential. I also have a pair of collapsable poles “Fizan Compact 3″ (from massdrop!) that are 5.6oz a pole, as sometimes it is handy to have ones that collapse (traveling with them in cars/planes, putting them away while one scrambles up/down rock)
* Wet Wipes are great. I repackage some into ziplocks. For ‘bathing’ if there is not a handy place to swim (or poor weather for swimming), as great TP, and can be used as a little cleaning cloth on pans / spoons / whatever.
* Make your own first aid kit – there are two wins doing this. One is there is a weight savings, and two is that because you went through and made the kit yourself you will know what everything is and is for. Various online resources for doing this. Mine is in a freezer bag inside a waterproof ditty bag and is made of mostly of tiny plastic bags I got on amazon with labels written on them in sharpie. The small one I had purchased was 11oz, this one is less than 5oz. There are various guides / ideas / examples online of how to pick what you need.
* Buying new lightweight gear can be pricey but you can find a lot of it used as well. Backpackinglight.com gear swap forum is handy place to look. As is ebay. You can also make lots of gear yourself, there are numerous DIY webpages and videos on seemingly anything from making your own down clothing to cuben fiber tarps / bags / etc. You can find tiny tubes and containers in the kitchen and bathroom and clean them after they are used up, etc.