T-Mobile said it will start to sell a mobile phone with computer-like features and WiFi. The phone, from Taiwan’s HTC, runs on a Microsoft operating system and has a minicomputer-like keyboard designed to make it easier for consumers to use the phone for emailing. The phone, branded the T-Mobile Dash, will go on sale on October 25 for $199 after rebates to people who sign two-year contracts. It is part of T-Mobile’s bid to boost revenues by getting more customers to use phones for more than talking.