This chapter summary was originally going to be (ecch!) a bulleted list. But if you read the Table of Contents, you'll see that we indeed covered a lot of ground in Photoshop 7, dealing with only two features. If you can take to heart (IOW, remember <g>) a handful of techniques here, you've already become more dynamic and powerful in expressing yourself with pixels.
Earlier in this book, I mentioned that selection-making is the most refined and sought-after feature in Photoshop. As a means to this selecting-stuff goal, we have covered three main features in Photoshop: layers, paths, and channels. Chapter 5 gets you into the creation of paths and also explores about a billion ways (okay, ten) to manipulate image channels to create more compelling, more evocative artwork.