Treating hypertension is known to decrease morbidity and mortality. Despite this 70% of patients do not have adequately controlled blood pressure. The main reason for this is non-adherence to recommended drug therapy. Although strategies have been developed to improve adherence many are time consuming and expensive. We propose to use communications technology to develop a novel means of improving adherence to antihypertensive therapy. We will conduct a randomised, single-blinded, controlled study to assess the impact of a real-time, automated reminder system on adherence rates. This will involve adapting two pieces of currently available technology - the electronic pill bottle and the Ambient Globe. The Globe will change colour in response to information received, via a wireless link, from the patient's electronic pill bottle. We hypothesise that this will provide patients with an up to date, but unobtrusive, reminder of their adherence status and thus effect positive behavioural change. We will measure the impact of this intervention on adherence rates as well as assessing patient views and the impact on provider workload. This trial will elucidate the role of communications technology in improving adherence behaviour and allow us to develop further strategies to tackle this major health issue.