I don't have a kindle. I do have a NookColor, which I like a lot, but there is no nookbook version of this book. Fortunately, I was able to download the kindle app to my smartphone without owning a kindle and so I have it available while I am out taking pictures.
The smartphone also comes in handy in doctor/dentist's offices while waiting to be seen.
Leonard Evens Professor Emeritus, Department of Mathematics, Northwestern University