Anyway, according to our past experiences, we have to say that we were quite lucky, finding often (in our institutional partners) people who did not underestimate the problem and allowed us to share archaeological data in specific project. The media we normally chose for this purpose is the webgis.
The image belows regards one of this projects, oriented to archaeological research and conservation in a small area (the territory of Vervò, in north-west Trentino, Italy).
The webgis was developed in 2009 by Giuseppe Naponiello using entirely Free and Open Source Software (soon Giuseppe will write a post with more technical information about it); the data come from the research of Alessandro Bezzi and are released with a Creative Commons license. The project was possible thanks to Dr. Nicoletta Pisu of the "Soprintendenza per i Beni Librari Archivistici e ArcheoLogici di Trento".
Actually you can visulize the webgis here.