22. A system, comprising: at least one network-based server comprising hardware; at least one network interface; a router subsystem, which serves as an interface to the Internet to manage communications between online Internet Protocol client devices and the network-based server; and non-transitory memory coupled to the at least one computing device that stores instructions that when executed by the at least one computing device cause, at least in part, the system to perform operations comprising: creating a user account at least partly in response to receiving account registration information from a user; providing an application software program for installation on a mobile computing device associated with the user; receiving from a first visitor to a web document of the user a communication request to communicate with the user via a communication interface displayed in association with the web document of the user; and at least partly in response to receiving a presence indication at the computing system that the application software program is online, transmitting, by the computing system, to the application software program installed on the mobile computing device associated with the user a text message entered by the first visitor into a text entry field, without the first visitor providing, and without revealing to the first visitor, a mobile communication device phone address of the user.
22. A system, comprising: at least one network-based server comprising hardware; at least one network interface; a router subsystem, which serves as an interface to the Internet to manage communications between online Internet Protocol client devices and the network-based server; and non-transitory memory coupled to the at least one computing device that stores instructions that when executed by the at least one computing device cause, at least in part, the system to perform operations comprising: creating a user account at least partly in response to receiving account registration information from a user; providing an application software program for installation on a mobile computing device associated with the user; receiving from a first visitor to a web document of the user a communication request to communicate with the user via a communication interface displayed in association with the web document of the user; and at least partly in response to receiving a presence indication at the computing system that the application software program is online, transmitting, by the computing system, to the application software program installed on the mobile computing device associated with the user a text message entered by the first visitor into a text entry field, without the first visitor providing, and without revealing to the first visitor, a mobile communication device phone address of the user. 31. The system as defined in claim 22 , wherein the text is transmitted over the Internet to the application software program installed on the mobile communication device of the user.