Searching for images

I showed Barb my slides and we discussed what sort of images would make sense for what's a fairly abstract talk about writing and editorial guidelines. I eventually decided upon a 'travel' theme -- a "What's New" shows you the terrain -- but finding images is still difficult. Maps are obviously relevant and very abundant online. Users vs. developers can be illustrated by tourists v. tour guides, but it's surprisingly hard to find an image that says "tour guide". After an hour or two of searching I only managed to find about half the images I need.