Lightweight, grassroots "observation" data format, with supporting tools!

Hi Folks,

There is an exploding growth of sensors. Here are a few examples of sensors:

- 	flood gauges
-	air pollution monitors
-	thermostat
-	stress gauges on bridges
-	mobile heart monitors
-	traffic Webcams

Sensors take observations. For example an air pollution monitor periodically measures (observes) the air pollution.

How do we structure the data generated by a sensor? Has anyone created a _lightweight_ data format for observation data? If yes, are there tools to process the data format?

I am aware of the OGC's Observations and Measurements stuff. [1] It's nice, but I am wondering if there has been a bottom-up, grassroots development of a lightweight data model for observations? 

/Roger

[1] OGC Observations and Measurements: http://www.opengeospatial.org/standards/om