I just finished The Perfect Vehicle: What It Is About Motorcycles by Melissa Holbrook Pierson. This is a book that every rider of a philosophical bent should certainly read. This book is part historical investigation into the early days of motorcycling, part travelogue, part paen to the Moto Guzzi (of which Pierson is an utter devotee), and very well written. Pierson's prose is very inventive and humorous, self-deprecating at times, and well informed. I get the impression that she's a quietly competant rider, rather than a brilliant, race-winning one, and you won't find tips for perfecting your lines or installing an aftermarket exhaust here, but you will find a wonderful exposition of what it is that draws us to our bikes, to the feelings that dwell in our minds on the back of our bikes, in the rain, at night, at speed.

I'd recommend it highly, and I'll be passing it on to my girlfriend tonight, to hopefully explain (in part) what I feel when I'm riding, in words more beautiful than those I can manage.