A very nice paper: Benford, S., Seagar, W., Flintham, M., Anastasi, R., Rowland, D., Humble, J., Stanton, D., Bowers, J., Tandavanitj, N., Adams, M., Farr, J. R., Oldroyd, A., and Sutton, J. (2004). The error of our ways: The experience of self-reported position in a location-based game. In Proceedings of the the 6th International Conference on Ubiquitous Computing. (UbiComp 2004), pages 70–87, Nottingham.

The use of positioning systems is an important but problematic aspect of ‘context aware’ applications. Through focusing on location-based games, we introduce the approach of self-reported positioning in which players explicitly and implicitly reveal their positions by manipulating electronic maps. A study of a game that piloted this approach demonstrates that self-reported positioning can be a reliable low-tech alternative to automated systems such as GPS. We contrast the strategies used by humans to generate position updates – reporting at landmarks and junctions and ahead and behind themselves – with automated approaches, drawing out implications for how we think of positioning error and design positioning systems.

Interesting because it deals with uncertainty about how LBS report people's location