A short note of heartfelt thanks to Tim Bunce, who was exceptionally kind in rummaging through my Amazon Wishlist and sent me Amit Singh's massive Mac OS X Internals - A Systems Approach and Herman Hesse's Siddharta.
After a short dip in each, both seem excellent nourishment for the mind - although I would advise anyone trying to lift Amit's 1600-page, 2-inch-thick tome to nourish their body first, take a deep breath and place their feet carefully before exerting themselves.
Finally, a technical book that is both enjoyable and, er... meaty.