"To achieve the data Web, organizations will have to make their own contributions to it—not just by providing access to data, but by exposing and making explicit the context that’s now only implicit in column and row headers, in cubes, in inscrutable metadata, or on Web pages. To share this context across domains, organizations will need the context to have a breadth and universality that it doesn’t have in its current closed environment." PricewaterhouseCoopers Technology report (Spring 2009)
It should be possible to use any Linked Data aware user agent against the data source when seeking to make additional mashups.
Jeni Tennison has a series of articles describing the process of creating Linked data in the context of the UK governments data project.
Best practice is to keep the knowledge about linking i.e. a Linked Data Space, separate to the substantive knowledge you are representing.
Ideally have purpose specific Linked Data Spaces (housing many Named Graphs) if you seek to make things a little clearer to data consumers and their agents.
Realizing a write-enabled Web of Data is outlined in the article Realizing a write-enabled Web of Data.