1. A computerized method for allowing a user to switch between interfacing with a service through a network or through short message service (SMS), the method comprising: executing, by a server computer, a chat service through which a first user at a first computer can communicate directly with a second user at a second computer, both the first computer and the second computer communicating with the chat service through a network; receiving from the first computer, by the server computer, a request to enable the first user to interface with the chat service through a mobile device of the first user using short message service (SMS) instead of through the network using the first computer; and configuring, by the server computer, the chat service to interface with the mobile device through SMS, comprising: communicating chat information through SMS to the first user's mobile device and communicating chat information through the network to the second computer such that the second user is unaware the first user switched to using the mobile device instead of the first computer; and communicating control information through SMS to the first user's mobile device such that the first user can control a full functionality of the chat service using SMS.