If your kids have outgrown the backyard swingset and it is still in good condition, it can be donated or sold.
However, if your swing set is rusty or unsafe, it can still avoid the landfill. Steel is an ideal material for recycling at your local scrapyard.
A local Yahoo group that posts items people who live near you want to get rid of. Everything is free – no selling, no bartering – all giveaways. If you’re not concerned with receiving a tax receipt for your donation, this is the site for you.
Craig’s List is a free classified listing service serving most major cities in the U.S. They also have Barter and Free sections where you can offer up your items.