Trainspotters, eagle-eyed bloggers, and tech detectives of all stripes have had a field day with last night's iPad commercial. At the very least, we got a pretty good look at some e-book prices, ranging from Ted Kennedy's True Compass: A Memoir ($14.99) to Three Cups of Tea: One Man's Journey to Change the World One Child at a Time by Greg Mortenson and David Oliver Relin ($7.99). All gripping reads, for sure, and all more expensive than Amazon. In addition to all that, TUAW has made note of a New York Times bu