I just got a Kindle--quite an amazing piece of technology. Far lighter than an actual book, it can hold thousands of titles. I started looking at what prostate cancer books are available in Kindle format, and there are quite a few. Not all, but a lot of the ones I like and refer to often. I will probably load up with a few, so I always have a reference library at hand.
If you haven't held a Kindle, you should give it a try. The display is not a computer screen. It's not LCD. There is no light shining from it. It uses real ink particles on a surface that looks like real paper. Battery life is impressive, since after arranging the text on the page, the device isn't using any energy to display it. Books on Amazon are cheaper than the paperback versions (Walsh's book, for example, is $11.55 in paperback, but $9.99 in Kindle format) and they download very quickly. I bought and downloaded a novel last night--Game of Thrones, about 600 pages--in a minute. You can literally think of a book and be reading it in a few moments. Want to read a major newspaper? You can buy today's copy--just today's, if you want--for the newsstand price and take it on the plane with you without messing with newsprint and all the rest.
I got the one that is $139. It doesn't connect via 3G, only Wi-Fi, which is fine with me, since I have wireless at home, work, and it seems to be in most coffee shops now as well. I also bought the leather cover.
Here are some prostate cancer books available in Kindle format.