Diluted magnetic semiconductors offer the possibility of adding the spin degree of freedom to the electrical and optical semiconducting devices that underpin modern technology. They are among the most investigated classes of material in applied materials physics. The principle approach to this has been to dope well-known semiconductors (generally II-VI or IV-VI systems) with transition metal ions at roughly the percent level to induce a ferromagnetic state. The first material for which this was achieved at room temperature was cobalt doped TiO2. A major question in these materials is whether the magnetic properties come from clusters of the transition metal dopants or whether, as hoped, homogeneous ferromagnetism is present. This is an ideal question for study using muSR. Here we propose to investigate samples of Co and Mn doped TiO2 to probe for cluster magnetism or long-range order.