When it comes to persuasive reasons to purchase an HDTV, nothing beats having compelling content—and lots of it. Add one more notch to the content totals: Discovery Communications announced last week that it will launch Discovery HD Theater. The company describes HD Theater as a new 24-hour network "which will transmit high-definition content in all the popular categories of entertainment offered by Discovery" including nature, history, world cultures, geographic explorations, science, education, travel, and a wealth of children's and how-to programming.