“The medium is the message,” Marshall McLuhan wrote in 1964, meaning that the form of the medium is part of every message and influences how the message is perceived. And this is even more true since the invention of the Internet with email, newsgroups, forums, and text chat. Another reading tip for this holiday season: “SEND: The Essential Guide to Email for Office and Home” by David Shipley and Will Schwalbe. GigaOm blogger Nancy Nally about the book: The authors of “SEND”...