Abstract-- The capabilities of embedded devices such as smartphones are steadily increasing and provide the great flexibility of data access and collaboration while being mobile. From the distributed computing point of view, fundamental issues in mobile computing include heterogeneity in terms of varying device capabilities (i.e., operating systems and various hardware platforms), performance characteristics and real-time behavior, and the ability to discover and interact with peers seamlessly. Web services are a family of XML based protocols to achieve interoperability among loosely coupled networked applications. We propose the use of Web services on embedded devices in order to solve interoperability issues in distributed mobile systems. We discuss various toolkits available for embedded devices and investigate performance characteristics of embedded Web services on smartphones. Our goal is to guide the design of Web services based applications on mobile devices, and provide estimat...