Last month, my column on electronic book readers drew fire from several quarters. There were those who couldn't believe I could recommend an electric appliance in this era of global warming. (Actually, the most environmentally benign way to read the newspaper, according to one study, might be with an EBR.) Others couldn't imagine ever giving up the feel of a paper book. (That's my difficulty, too, but I'm not crazy about deforestation either.)

In any event, this month, I want to recommend another tree-saving alternative that I have personal experience with.

No, it is not the library. I assume everyone is already aware of what a tremendous resource a library is, and how environmentally sound, not to mention socially just by making books, periodicals, computer and Internet access available to people who cannot afford them.

But even the library, wonderful invention that it is, has some drawbacks. Due dates, for one. The need to carry through with the intention of reading a particular book at a particular time, for another. And the inability, when reaching the end of a perfect book, to declare it a keeper.

Plus, a library doesn't do anything about the unloved books moldering on your bookshelves now.

Book-trading through swapping websites is the alternative. They work like this: You join. You post the names of books you're ready to trade away. You look for the books you want to acquire. Trades are arranged (not necessarily between the same two people.) You mail your old books and receive new ones.

That said, there are important differences between the services -- in cost, convenience, trading process and availability of your kind of books -- that may make one or the other more to your liking. Also, some sites allow you to trade other media (DVDs, CDs and video games) along with books.

A year or two ago, I tried Zunafish, which is a very hands-on trading service. Whenever you click on a book you want, an email goes out to the people offering it, with an invitation to search your list of books and propose a trade. You're free to accept or reject any proposal.

Alternatively, someone else may initiate the process by selecting a book that you happen to have. In that case, you are invited to propose the trade.

Either way, the process was way too involved for me, but then, I never was much of a shopper. I always wanted to cut to the chase and buy.

More recently I tried Swaptree, which suits me to a tee. With Swaptree, you create two lists -- one of the "items you have" and one of the "items you want." Based on these lists, the system arranges the trades for you. All you do is approve them. There is no need to evaluate proposals or browse other people's lists. To keep the trades coming, you just need to keep your own lists well-populated. I could see how this degree of automation might be the very thing some people would not like about Swaptree, but for me, it's what makes it work.

Another popular service, which I haven't tried, is Bookins. Like Swaptree, it automates the trading process. However, where Swaptree considers all books equal, Bookins assigns them points based on popularity, awards, etc. The trades you can make are determined by the points you have available. Unlike the other systems I'm familiar with, Bookins tracks your shipments and actively helps resolve problems.

Both Swaptree and Bookins calculate and print the postage required for your shipments, which cuts out a trip to the post office (environmentally advantageous if you would have driven there). You can make shipments greener by reusing packaging.

The trades I have made over the last couple of months have gone off without a hitch. Everything came in good condition, as advertised, and the wait was never too long. With Swaptree, traders are encouraged to work out any difficulties between themselves if possible (via the website's messaging system -- no one gets your personal email address), and one trading partner did contact me to say she'd mistakenly put the wrong name on the package. It arrived just the same. At the end of the process you're expected to rate your partner. I've only had reason to give good ratings so far.

When a package does arrive, it feels like a gift. Although you pay the postage for your shipment and a dollar or two per trade with some services (not Swaptree), the cost is nominal. The whole process lies more or less outside the money economy within the context of a book-loving community. This, alone, makes book-trading worth a try.

—Sheryl Eisenberg

ONLINE RESOURCES THE GUARDIAN Turning Over an Old Leaf GOOGLE (search results) Book Trading Websites LIBWEB Global Directory of Libraries ABOUT.COM Ten Top Reasons Why Trees Are Important LIBRARY THING Catalog Your Books Online (and search for books you want to acquire to see which trading sites have them.)

No-brainer. Even if you can't see your way to buying fewer books, you can print less paper at work, recycle all the paper you use and buy post-consumer recycled paper.

Did you know... If every household in the United States replaced one roll of virgin fiber paper towels (70 sheets) with 100 percent recycled ones, we could save 544,000 trees. Make that two million if every household made one similar change with toilet paper, tissues and napkins.

The value of forests. Among their many benefits, forests help to prevent erosion, conserve and purify water and store carbon dioxide that would otherwise be contributing to global warming. They also provide habitat for up to 90 percent of known terrestrial species, according to the U.N. Environment Programme.

Everything has a downside. In the case of book-trading, it's the reduction in authors' royalties. In that sense, an electronic book reader is better because writers still get paid (though not necessarily enough).