Summary: ExtraBITS this week span the gamut, starting with Tonya Engst’s appearance on the Tech Doctor Podcast, Cult of Mac’s comparison of print and ebook prices for textbooks, some juicy Apple secrets revealed in the Apple-Samsung patent suit, a site that lets you navigate recent Mars photos using an iOS device’s gyroscope sensor, Lex Friedman’s explanation of how to turn on Google’s two-factor authentication, and a collection of reminiscences on HyperCard’s 25th anniversary.<p> </p><p>Read the <a href="http://tidbits.com/article/13207">full article at TidBITS</a>, the oldest continuously published technology publication on the Internet. To get a full-text RSS feed, help support our work and <a href="http://tidbits.com/member_benefits.html">become a TidBITS member</a>! Members also enjoy an ad-free version of our Web site, email delivery of individual articles, the ability to make long comments with live links, and discounts on Take Control orders and other Apple-related products.</p>
