nWhat’s the difference between a TV show and a phone call? If you’re a Google data center, there isn’t any.nWhich is why it’s not only Hulu-style streaming television shows and Skype-style video calls that may soon be added to the growing list Google services. If a computer can do something new, Google data centers can be doing it this afternoon.nGoogle’s principle business involves selling small classified ad-style text messages in connection with Web searches. To run that business, it’s been required to build dozens of shopping mall-sized data centers all around the world. (Google won’t disclose the exact numbers.) Inside these centers are huge rooms with rows of computer racks. Defying Hollywood stereotypes of quiet sterility, they are usually noisy and cold, from all the air conditioning.n n n