One of my guiding principles of going on any kind of trip is to travel light. That means not carrying any more than absolutely necessary.
Contemplating a trip to several countries, one stiff deterrent to living up to this principle can be the number of guidebooks you find yourself tempted to schelp in your backpack.
The obvious solution to this conundrum is to download e-book versions* of several Lonely Planets. It turns out, Lonely Planet has already made it possible to do even better than that. You can buy and download only the chapters of your choice from the publisher's array of guidebooks.
TravelVice has penned an extremely thoughtful post on this topic, full of some creative options -- even for people who don't want to carry a notebook computer or PDA with them!
* I noticed that various Lonely Planet books are presently not available for download onto an Amazon Kindle. LP probably figures they can make more money selling the electronic copies on their own website. Nevertheless, the Kindle offers a great way to carry your other reading material, especially on an extended trip.