by Brook Wilkinson

I blogged a few months ago about Lonely Planet's new Buy by Chapter program, which lets you purchase just the sections of a guidebook that are relevant to your trip. Back then, the service was available only for the Latin America series, but it's now been expanded to include the books for North America, Africa, the Caribbean, and the South Pacific -- almost 100 guides in all.

Let me take this opportunity to say it again: This is a great deal, both financially and environmentally. Many's the time that I've lugged a multi-country guidebook on a single-destination trip, simply because it was the most up-to-date source of information I could find. Now, if I want to take a weekend trip to San Diego, I can buy just that city's chapter for $3, instead of the entire California guide for $23. When you purchase a chapter, you'll receive it in PDF form, so you can save it on your computer and print out only what you'll need on your trip. If you buy three or four chapters, you'll save an additional 20 percent; buy five or more and you'll save 35 percent. A good deal for you, and for the earth.