A method of allowing a user to roam from one wireless network to another, the method comprising: establishing a connection between a wireless mobile device and a first wireless network, wherein the connection allows the wireless mobile device to interact with an Internet-based application; tracking a state of interaction between a user of the wireless mobile device and the Internet-based application by storing data representing user interaction events; terminating the connection between the wireless mobile device and the first wireless network; establishing a connection between the wireless mobile device and a second wireless network; and sending, to the Internet-based application, data representing a state of interaction of the user of the wireless mobile device with the Internet-based application prior to terminating the connection between the wireless mobile device and the first wireless network, whereby the user can interact with the Internet-based application via the second wireless network from said state of interaction; characterised in that the step of establishing a connection to the second wireless network comprises: sending identity information from the wireless mobile device to a server on the second wireless network; sending a request to authenticate the wireless mobile device from the second wireless network server to a server associated with a third party; and either authenticating the mobile device with the third party server; and sending confirmation of such authentication to the second wireless network server; or determining that authentication of the wireless mobile device must be provided by a fourth party; sending a request to authenticate the wireless mobile device from the third party server to a server associated with the fourth party; and sending confirmation of such authentication to the second wireless network server. establishing a connection between a wireless mobile device and a first wireless network, wherein the connection allows the wireless mobile device to interact with an Internet-based application; tracking a state of interaction between a user of the wireless mobile device and the Internet-based application by storing data representing user interaction events; terminating the connection between the wireless mobile device and the first wireless network; establishing a connection between the wireless mobile device and a second wireless network; and sending, to the Internet-based application, data representing a state of interaction of the user of the wireless mobile device with the Internet-based application prior to terminating the connection between the wireless mobile device and the first wireless network, whereby the user can interact with the Internet-based application via the second wireless network from said state of interaction; characterised in that the step of establishing a connection to the second wireless network comprises: sending identity information from the wireless mobile device to a server on the second wireless network; sending a request to authenticate the wireless mobile device from the second wireless network server to a server associated with a third party; and either authenticating the mobile device with the third party server; and sending confirmation of such authentication to the second wireless network server; or determining that authentication of the wireless mobile device must be provided by a fourth party; sending a request to authenticate the wireless mobile device from the third party server to a server associated with the fourth party; and sending confirmation of such authentication to the second wireless network server. sending identity information from the wireless mobile device to a server on the second wireless network; sending a request to authenticate the wireless mobile device from the second wireless network server to a server associated with a third party; and either authenticating the mobile device with the third party server; and sending confirmation of such authentication to the second wireless network server; or determining that authentication of the wireless mobile device must be provided by a fourth party; sending a request to authenticate the wireless mobile device from the third party server to a server associated with the fourth party; and sending confirmation of such authentication to the second wireless network server.