[Here are a couple of interesting pointers to using SOA and grids for wireless and portable devices. Thanks to Susan Baldwin and Lee Mcnight for these pointers -- BSA]
NEMOS: Mobile-Agent based Service Architecture for Lightweight Devices
NEMOS is a framework for deploying a Service Oriented Architecture (SOA) on lightweight devices such as sensor networks and cell phones, allowing integration of such mobile networks with the SOA architectures available on the Internet. Execution and coordination of service compositions are performed using highly compact mobile agents, in a lightweight environment tailored for distributed task control. Device services and resources are described using ontological metadata, permitting rich data semantics and facilitating service compositions for interoperability between network devices. This approach can bridge web service architectures deployed on the Internet (such as the Web Services architecture) with ad-hoc networks of mobile devices.
More information found in the NEMOS paper: http://www.ugrad.cs.ubc.ca/~d0r4/NEMOS.PDF
Wireless Grids Corporation (WGC) is just one company working in the Wireless Grid problem space, so I can only tell you what we are working on. We are using what is currently a proprietary middleware that is based on a Couple of simple protocols. We are using ZeroConf for local discovery and Some simple REST based API's as a control channel. What are we controlling? Well,we use our software to control things like UPnP devices and Samba based File sharing in Windows.
Basically, we are trying to create a grid of resources and controllers inside the home network that will help people utilize the resources they already have as well as enable new interactions. e.g. Windows does file sharing...but it doesn't make it easy to scale file sharing up to several machines with several users in a single house. Most people will never use Windows file sharing because of this.