Backpack is a great way to keep travel plans organized.
Let's say you've got a bunch of info to keep track of for a trip to Seattle and BC. Flight info, ferry info, hotel info, a restaurant to check out, etc. Instead of keeping all those links and emails floating around, you can add them to a Backpack page.
Want to be able to easily access all that info straight from your email inbox? Use the "Email me a copy" option in the footer of your Backpack page. Backpack will send you the contents of the page via email.
Now you've combined all those links and notes into a single email for quick reference. That's a lot cleaner than having dozens of notes and confirmation emails floating around your inbox.
Related:
Tips on using Backpack for travel planning
Macworld calls Backpack "a good way to keep track of travel plans"