Access to the Computational Grid is currently tied to the laptop/desktop environment since previous Grid client development has been concentrated in this area. This paper presents the design and implementation of a new lightweight Grid client that provides the same level of functionality and security as its desktop counterparts whilst conforming to the limitations and restrictions of a PDA Java runtime environment. This opens up a new area of Grid Computing access: secure and flexible job submission and monitoring to dependable, persistent, powerful and consistent computing services provided by a Grid has been freed from static environments into the mobile domain using standards-based platforms, protocols and components: J2ME, X.509 certificates, SSL connections and IEEE 802.11b wireless networking.