Modern lifestyle corresponds with high personal mobility. People want to work or use leisure-time applications while on the
road. Modern mobile communications systems allow to meet these requirements for the first time. Advanced new features like
user positioning allow sophisticated applications that are not possible in the fixed Internet or traditional cellular networks.
Still, application development for the Mobile Internet is a complex task. Users have special demands because of the mobile
environment. Stringent technical constraints are imposed by mobile networks and mobile devices.
In this paper we present a prototype of a mobile application for UMTS. It is called LoL@ (Local Location Assistant) and implements
a tourist guide for users in the city of Vienna. We discuss user interaction and interface design, design process, and technical
solutions used to implement the application. Because of the initial lack of powerful PDAs, currently a laptop is used as terminal.
Keywords Location Based Service - Electronic Guide - Mobile Internet - Semi-Formal Requirements Specification