Enriching a mobile device with the ability to detect its location can enable the provision of a range of Location Based Services to its user. Outdoors, the location detection facility is sufficiently provided by GPS, however GPS is not suited to the challenge of non-line-of-sight indoor environments. In these environments smaller scale location estimation techniques must be employed. Due to their ubiquity, WiFi signals are a commonly employed indicator of location; knowledge of the identity and intensity of these signals throughout an environment can allow the estimation of the receiving device’s location. This paper outlines work towards the development of efficient, privacy conservative positioning algorithms suitable for deployment on commonly available mobile phones. For a number of algorithms, the frequency of correct location prediction is presented along with the execution time on a real mobile phone.