I spent a good portion of last night critically analyzing my pack weight. Although I can't do much on my budget with my 4lb 9oz pack and 5-6lb sleeping bag, I figured I might as well save a few ounces here and there on other items. Aside from going into detail, because this is not an ultralight backpacking forum, I'll just cover some general equipment that can save a ton of weight at limited cost to you.
Replace your pot's cover with a pie tin.
The pie tin lid for my .9L pot weighed in at 4.5g (grams!). I used a needle nose pliers to kink the edges so it formed a lip and fit perfect on the pot. The stock lid weighed 50g, a savings of 45.5g (1.6oz).
Platypus water reservoir ($9 for 2.5L)
I came across these last night. A 2.5L reservoir weighs 1.2oz! Compare that to my 3L camelbak at 7oz, you can easily see a weight saving potential here.
Throw away your Nalgenes
An empty Nalgene easily weighs 1/3 lb each but an empty Gatoraid bottle weighs 1.7oz and will last almost as long. The only difference is I don't think the Gatoraid bottles can stand up to boiled water, though I could be wrong. If I am, Gatoraid is the obvious winner.
Mesh ditty bags
Although using your fancy lightweight stuffsacks may seen obvious, a simple mesh nylon ditty bag (drawstring kind) can weigh as little or even less! Use them as container bags for misc items like your first aid kit, carabiners, toilet paper (though I'd recommend a ziplock for waterproofing), etc. These ditty bags usually come with your cooking pot or some other equipment and are easy to find. I weighed mine at 9.9g (0.35oz) and haven't even replaced the nylon cord and friction stopper with a lighter option!
Fleece > Wool
Although I have yet to do extensive field tests, polar fleece (commonly referred to as simply 'fleece') is a synthetic copy of wool and is supposed to be better, lighter, and more recyclable than wool. It still repels water, provided thermal insulation when wet, dries quickly, is cheaper, and weighs a lot less.
Multiuse items
Multiuse items saves a ton of weight. Those spare wool socks? Mittens! Don't bother bringing mittens unless it's winter while you have spare wool socks at hand (haha, pun). Those spare bootlaces? Drop em if you have some paracord on a lanyard or in your pack. Redundancy is stupid.
So let's say you replaced your items following the ideas above... how much weight would you really save and how much of an investment would that be? Well, on average, you save 11oz (.687lbs) at a cost of only $10 (assuming you can find a free pie tin)! This does not include the weight savings from a ditty bag, fleece clothing or multiuse items so you could be saving 5x as much weight!
So those are a few simple, cheap ideas to lighten your load by pounds! Try as I might, I can't get my pack weight (including water, food and fuel) below 25lbs for a weeklong trip. I blame this on my 6lb sleeping bag (free, I'm too cheap to buy a new one) and my almost 5lb pack. Oh well, live and learn.

