Digital content is ubiquitous in all parts of life today. In particular Web 2.0 technology changed the way of communication. It allows everybody to contribute to digital content and to reach a large audience. The possibility to contribute also has an effect on the desire to contribute to ``real world'' matters. At the same time an incredible amount of information is online accessible without any effort. In many cases this enables us to find specific information fast and without leaving our current location.

This forces public knowledge places, like libraries or museums, to re-think their role as knowledge providers. These institutions have to become places of social interaction which provide meaningful collections of objects and information as well as space for creativity.

Visiting a museum is a great experience. Seeing objects, which have texture and physical characteristics combined with the history and the story of the exhibit, is an adventure and beneficial for engagement with a certain topic. Museums store much more objects, than they can present. These exhibits are not accessible for the public and sometimes not even for research purposes. It is a challenging task for curators and museum professionals to select objects for a meaningful and appealing arrangement. Re-creating and re-arranging exhibits in museums is mostly prohibited for visitors, because shown exhibits are often one of a kind, expensive, or damageable.

During the last decade museums build large databases to index their objects. In Parallel Exhibitions we make use of these databases to invite visitors to become co-curators in museums. We design and implemented an application, which allows museum visitors to contribute to the exhibition design. Curators can additionally include physical exhibition in the virtual interaction space to create a close relationship to other exhibits in the museum.

To evaluate our concept and our application we conducted a field test in a museum as well as an online study. In addition we interviewed possible users and museums professionals. We observed a rich social interaction around our application in the field study and the studies confirm that visitors have an interest to contribute to exhibitions they are visiting, both locally and on social media.