There’s a new movement in business that probably just about any PerkStreet fan — surely already interested in ways technology and forward-thinking can make your financial life better — could appreciate. It’s called “collaborative consumption,” and it’s all about sharing.

The trend is finding context in a new book, What’s Mine is Yours: The Rise of Collaborative Consumption, written by Rachel Botsman and Roo Rogers and released at the end of last month. The text reveals “how in the 20th century of hyper-consumption we were defined by credit, advertising, and what we owned, and how in the 21st century of Collaborative Consumption we will be defined by reputation, community, and by what we can access.”

Leading the collaborative consumption movement are a series of super smart new companies aimed at helping people have all the convenience of the last century while consuming a heck of a lot less in the next one.

The best part for budgeters?

Collaborative consumption means new ways to save money on things you used to dump loads of cash on. It also means making money back on purchases you figured were sunk costs. Here are a few new companies you should check out to get extended value on things you’ve already purchased:

Real Estate You’re Already Paying For:

AirBNB.com – Based in San Francisco, Calif. – If you’re traveling but don’t want to pay for all the amenities of a hotel or true bed and breakfast, this new company lets you rent a room in a person’s house for a short stay. Gone are the days of window signs reading “Room for rent,” but that doesn’t mean you can’t make some money off your extra space. With AirBNB.com you can rent out your extra rental property, private room, entire apartment, bed and breakfast, boutique hotel, castle, or treehouse using the site.

Things You’ve Bought But Never Use:

Zilock.com – Based in Brussels, Belgium – It’s hard to justify buying things you’re not going to use very often. Likewise, watching expensive purchases go unused while collecting dust in your crawlspace seems like a waste. These are the fundamental ideas behind Zilok, which lets anyone rent anything to someone in their community. Camera equipment and jewelry are big ticket items here, but people rent one another everything from small power tools to Ferraris on this site.

Entertainment That You’re Now Bored With:

Swap.com – Based in Boston, Mass. – Do you have about a million DVDs, CDs, books and video games lying around your house you don’t use anymore? We thought so. At the newly re-branded Swap.com (formerly swaptree.com), you can swap all of those goods for different ones of equal value. There are currently some 5.5 million pieces of media waiting to be swapped on the site. Now’s your chance to stretch some brand new value out of these things you bought long ago.

Kids Clothes That Aren’t Worn Out:

ThredUp.com – Based in San Francisco, Calif. – You know how parents of kids in the same age groups are always swapping clothes with one another? Imagine you had access to a million people with kids who just outgrew their clothes. Imagine those clothes were your child’s size. Then imagine all of those people could give you those clothes in exchange for bigger clothes their kids could wear. This is the premise behind ThredUp.com. Swap your child’s gently used clothes for for someone else’s.

Land You’re Already Paying For:

SharedEarth.com - Based in Austin, Tex. – Where are people turning when they want a garden but don’t have anyplace to put it? SharedEarth.com; that’s where. Whether you have acres of fertile land or a fire escape fit for a few tomato plants you’d like to rent out, SharedEarth.com helps you lend your land to someone who wants to till it. As movements to support local farming grow, crop sharing is becoming more and more popular both in and out of urban areas. SharedEarth.com just makes the match — you decide how and when you’d like to be paid for your topsoil.

Collaborative consumption also includes sites like CraigsList.com and eBay, where you can buy and sell things second-hand anywhere in the country. If you’re looking for a more specific sharing, lending, or renting exchange, there are all kinds of sites like the ones above popping up. Any one of them can be a great way to earn a little extra cash to pad your budget. Just remember that collaborative consumption is all about community — don’t drive too hard a bargain and everyone will win!

What are your favorite new, cutting edge ways to earn extra cash? Let us know in the comments section below.

Another super smart way to earn extra money is by applying for a PerkStreet Financial Cash Back Debit Card. You can earn 2% Cash Back on everything you buy, and 5% in specific categories. Check back at the PerkStreet Blog for sound financial advice every day!