The utilization of context (such as user location and user profile) opens up many new avenues for encouraging social interaction. The web-based GUIDE system enables visitors to the city of Lancaster to interact with an information model that represents the city via a hand-held and context-aware tourist guide. Our current work is focusing on extending the functionality of the (previously single user) GUIDE system by making parts of the information model public. In particular, the physical location of visitors can now be represented in the information space in order to enable a form of social awareness among city visitors. In addition, visitors can also change the information space by, for example, augmenting existing descriptions of the city's attractions with their own ratings. We believe that explicitly capturing and tagging the context associated with ratings provides a powerful mechanism for automatically tailoring information presented to the user.