To date, mobile services have failed to match the explosive growth of the World Wide Web. This, we argue, is because current services are difficult to use, design and deploy. In this paper we describe a concept for a new class of services, addressing these issues. We call these services Simple Mobile Services (SMS). SMS will be simple for users to find, use, and trust; similarly they will be simple for providers to develop and deploy. Like the Web, they will provide technology and operator-independent end-to-end connectivity. But unlike conventional Web-based services they will target specific locations of interest to specific classes of mobile user with specific needs. We propose a design methodology and a set of related tools for the creation of SMS - based on the Model Driven Architecture (MDA) approach. We show how this methodology can support the design and deployment of SMS by service providers with limited technical expertise.