Museums are both appealing and challenging as an environment for indoor positioning research. By nature, they are dense and rich in objects and information, and as a result they contain more information than a visitor can absorb in a time-limited visit. Many research projects have explored the potential of novel technologies to support information delivery to museum visitors. Having an accurate visitor position is a key factor in the success of such projects. In spite of numerous technologies experimented with, there is no prevailing indoor positioning technology. Each technology has its benefits as well as its limitations. In addition, museums have their own constrains when it comes to installation of sensors in their space. In the framework of the PIL project, a flexible "light weight" proximity based positioning system was developed and deployed at the Hecht museum and a general framework for indoor positioning is proposed. The inherent limitations of the basic technology are addressed by an abstract reasoning layer and by a dialog with the user.