Have you heard of Freecycle? There might be one in your area.
Freecycle is simply an online group where you can post things you no longer need and give them away for free. You can also post items you want, and if someone has one to give, voila`, it's yours!
I think Freecycle rocks. We're in the process of clearing out a lot of unneeded stuff. My criteria for what I keep has gotten a little tougher over the years, mostly due to sheer need to move quickly through it all. The list goes something like this:
If I'm keeping it because:
1) It's beautiful, then it needs to be displayed, not stored.
2) It's useful, it needs to be useful now or in the immediate future (12 months or less). And it needs to have a regular home.
3) It's sentimental, then hopefully it's also beautiful, and back to rule 1. If not, then I think hard about it and decide if storage is worth it in the long run. And if someone else can really use it now, it still might not make the cut.
If it get's pitched, then here's the list:
1) If someone I know can use it, great, it goes to them.
2) If not, can I sell it? Ebay, craigslist?
3) If not, then Freecycle.
4) If not, than hopefully thrift store
5) Finally, trash...:-(
Here's where Freecycle becomes really cool. You find your local Freecycle. Google it, many are listed as Yahoo Groups. Lots of areas have them. You get added as a member. This is usually a simple approval process where you learn the rules, which are simple things like only free things get listed, and how to add your area to the post so people know where they have to drive to to pick it up.
Aha! Did you get that last line...people will come to you, and take away your unwanted stuff! They get something they want or need, and it's magically (to me, anyway!) gone!
Oh, a final idea for clearing out...if you live on a well traveled road, as we currently do, don't underestimate the usefulness of hauling things out to the curb and placing a free sign in front. More magic! We place probably 2 pick up truck loads worth of unwanted but still useful items out by the street this summer and they just disappeared. All of them!
This is especially true of things like building materials that your local resale shop won't take, but someone can still use, and would otherwise end up in the landfill (at your expense, and all of ours, in the long run).