This paper is concerned with developing personal computing aids for the mobile fieldworker. A description of mobile computing and context-aware technology is given, suggesting how hand-held computing devices that are aware of various factors of their userís environment (such as location) could be helpful. In particular, the concept of a stick-e note is introduced as a general-purpose context-aware technology that we have developed. The needs of fieldworkers and the suitability of stick-e note technology to their tasks is addressed, and a number of areas where stick-e note technology could help are identified. The design of a prototypical sticke-e note system that attempts to meet these needs is introduced and an account given of an extensive trial of this prototype in assisting in a behavioural study of giraffe in Kenya.