In this three year European Project we developed a linked data approach to live environmental data.
The public deliverables explain the process in more detail and the demonstrator.
Try this link to see a summary endpoint for one particular place (Boscombe) and time:
http://doc.api.channelcoast.org/observations/cco/boscombe/Hs/latest
(will transform itself into a url for the latest sea state readings for Boscombe.
In a normal web browser this shows the HTML version of the data - note that the units for measurements are defined in terms of the SWEET ontology for example.
http:/id.api.channelcoast.org/observations/cco/boscombe/all/20111111006/summary
shows a summary for a specific time.
You can try directly requesting rdf using something like:curl -H "Accept: application/rdf+xml" http://rdf.channelcoast.org/observations/boscombe
Which will provide an overview of the sensors .
Our tutorial material provides notes on how to write these mashups.