During the trip, each of us will have an opportunity to talk with students. We'll visit schools, of course, but we'll also meet them in parks, on the street, and elsewhere. Last year, many of our teachers found that bookmarks that their students had made about California or their hometowns were extremely popular. This may appeal more to middle school teachers than to the high school crowd, but it is a great way to involve your current students in your upcoming adventure. The bookmarks should be colorful and on card stock. Make them more durable with clear tape. Be sure to have the students include their names on them. It's a great extra credit project.
Now -- what might high school students exchange? Surf shop stickers (carefully reviewed!) are one place to start. Pencils with school names and other personalized items are popular. Maps with photos?
Let's brainstorm!