Sprint today announced a new text-messaging service that further closes the gap between cell and landline phones. The carrier's Text to Landline service will enable Sprint customers to send a text message to any 10-digit landline phone. A sent text message is converted to a voice message, the recipient's phone rings, then the message is read to them. The recipient can even respond by recording a voice message that will be sent back to the sender. It sounds like a cool feature to me, and the best part is that Text to Landline won't cost extra.