A cellular mobile device comprising: a transmitter and receiver to send and receive cellular communications in the form of radio frequency signals; a microprocessor; an operating system configured to execute on the microprocessor to provide an operating environment of application software; a multi-service virtual private network, "VPN", client registered with the operating system as a single application, wherein the multi-service network client comprises: a VPN handler to establish a VPN connection with a remote VPN security device, wherein the VPN handler is configured to encrypt outbound network packets and to decrypt inbound network packets to securely tunnel the network packets between the cellular mobile device and the remote VPN security device; a data acceleration module configured to exchange network packets with the VPN handler and to apply at least one acceleration service to the network packets, the at least one acceleration service comprising application-specific protocol optimization for control flows within the network packets, and configured to provide a client-side decompression service that operates in conjunction with an upstream acceleration device, wherein the data acceleration module is configured to maintain a phrase dictionary that is synchronised with a phrase dictionary of the upstream acceleration device; a security manager to receive the decrypted inbound network packets from the VPN handler and to apply anti-virus and spyware services to the decrypted network packets, and to provide an interface by which the VPN handler determines whether a user of the cellular mobile device has activated and registered the security manager; and a VPN control application configured to provide a unified user interface that allows a user to configure the VPN handler and the data acceleration module; wherein the VPN handler is configured to require an affirmative indication from the security manager prior to establishing the VPN connection with the remote VPN security device. a transmitter and receiver to send and receive cellular communications in the form of radio frequency signals; a microprocessor; an operating system configured to execute on the microprocessor to provide an operating environment of application software; a multi-service virtual private network, "VPN", client registered with the operating system as a single application, wherein the multi-service network client comprises: a VPN handler to establish a VPN connection with a remote VPN security device, wherein the VPN handler is configured to encrypt outbound network packets and to decrypt inbound network packets to securely tunnel the network packets between the cellular mobile device and the remote VPN security device; a data acceleration module configured to exchange network packets with the VPN handler and to apply at least one acceleration service to the network packets, the at least one acceleration service comprising application-specific protocol optimization for control flows within the network packets, and configured to provide a client-side decompression service that operates in conjunction with an upstream acceleration device, wherein the data acceleration module is configured to maintain a phrase dictionary that is synchronised with a phrase dictionary of the upstream acceleration device; a security manager to receive the decrypted inbound network packets from the VPN handler and to apply anti-virus and spyware services to the decrypted network packets, and to provide an interface by which the VPN handler determines whether a user of the cellular mobile device has activated and registered the security manager; and a VPN control application configured to provide a unified user interface that allows a user to configure the VPN handler and the data acceleration module; wherein the VPN handler is configured to require an affirmative indication from the security manager prior to establishing the VPN connection with the remote VPN security device. a VPN handler to establish a VPN connection with a remote VPN security device, wherein the VPN handler is configured to encrypt outbound network packets and to decrypt inbound network packets to securely tunnel the network packets between the cellular mobile device and the remote VPN security device; a data acceleration module configured to exchange network packets with the VPN handler and to apply at least one acceleration service to the network packets, the at least one acceleration service comprising application-specific protocol optimization for control flows within the network packets, and configured to provide a client-side decompression service that operates in conjunction with an upstream acceleration device, wherein the data acceleration module is configured to maintain a phrase dictionary that is synchronised with a phrase dictionary of the upstream acceleration device; a security manager to receive the decrypted inbound network packets from the VPN handler and to apply anti-virus and spyware services to the decrypted network packets, and to provide an interface by which the VPN handler determines whether a user of the cellular mobile device has activated and registered the security manager; and a VPN control application configured to provide a unified user interface that allows a user to configure the VPN handler and the data acceleration module; wherein the VPN handler is configured to require an affirmative indication from the security manager prior to establishing the VPN connection with the remote VPN security device.