Trends towards lower levels of physical activity have raised health concerns. Tools to capture, store and use information about physical activity might improve motivation to increase the level of such activity. This is especially important for Type 2 diabetes, since physical activity is one of the key components in achieving healthy blood glucose values. Over a period of four months, 15 people with Type 2 diabetes provided us with input on how a mobile system needs to be put together. Generally, they answered that such tools must be integrated as well as possible with their other daily tools and clothing. Based on their inputs, we built a sensor system for monitoring physical activity. The system automatically and wirelessly reports the accumulated number of steps taken, using a mobile phone as the patient terminal. We asked 1001 persons about their use of step counters/pedometers. About 6.5% of them use such a device daily and about 20% daily, weekly or monthly. Our concept differs from others of this nature in its simplicity, size and integration with other relevant patient data. It is fully manageable by patients themselves as a self-help tool.