The 510 is the first device in a new lineup of HP smart phones to be unveiled in coming months, an HP spokeswoman said. In addition to operating in both Wi-Fi and cellular networks, it provides more than 20 voice commands to allow hands-free operations for mobile workers. Users can reply to e-mail with a voice response without typing, she said. A Bluetooth headset will allow users to listen to e-mail and text messages through a text-to-voice feature.