A treadmill reading rack is one of those investments that you never consider undertaking until you find out from your friends that the third world war has started. You see this is the problem with too much physical activity, you tend to stay disconnected from the rest of the world in terms of news.
A reading rack is not that much of an expense anyway, it costs about 15 bucks and it will last you more than the treadmill. The problem is that different treadmills may require different reading racks, so you would better make some measurements beforehand so you don't end up with the wrong reading rack.
Another thing you should be careful when purchasing a reading rack is to make sure that the treadmill itself has a program, which is based on your heart rate, otherwise you might find yourself exhausted after such a session. You see it's really hard to check that heart rate when you have that nice Tolkien story in front of you.
A common mistake made by many people is to attempt to use the reading rack on the treadmill to compensate for all those readings they missed in college. Remember a session of treadmill training doesn't last, or at least it shouldn't last more than 40 minutes, so please choose your books carefully.
Of course the use of treadmill reading racks has seen an abrupt decline since some manufacturers began adding cd players to their products, it was inevitable I guess, but as soon as they start putting real television streams in those LCDs the hell will break loose and the reading rack industry will go down. Oh wait… There isn't a reading rack industry. Most of these are supplied by the treadmill manufacturers themselves anyway.
Now to suggest a short list of must read books for your reading rack I'd start with some good fantasy books, as these always tend to give wings to my legs. What can I say I'm the impressionable type. Never read Russian novels, they always tend to make the exercise harder, don't know why really. Trust me on this one, it's tested.
The best place to start finding the appropriated reading rack id the treadmill manufacturer's site. They usually offer a lot quite a lot of this type of gizmos and will be more than happy to take your money. They always are.
Bottom line is that a treadmill reading rack is an inexpensive investment which will surely make your training more enjoyable and no matter what your friends say, you will be able to have an informed opinion of your own.