A resource with links to useful articles. (This may be too like the Links page to be useful - that should emerge in time.)
Peter Weiss's "Borders in Cyberspace" paper about the relative benefits of closed and open access to public data. Here's the HTML version; here, the PDF, here.
April 4: Locus responds to the Free Our Data campaign. Locus is a trade association "established by a group of private sector companies to raise awareness and promote a healthy competitive market in the provision and use of public sector information".
Ordnance Survey challenged to open up The inventor of the world wide web wants access to Ordnance Survey data - and the freedom to manipulate it as he sees fit.
Guardian, March 9: Give us back our crown jewels by Charles Arthur and Michael Cross (Guardian). The first article in the campaign. (It attracted quite a lot of attention, as you can see by this Google search.)