I first came across the idea of “government as a platform” when I was interviewing Tim O’Reilly earlier in the year. Tim’s quickest way of explaining “gov as a platform” was using the iPhone as an analogy: i.e. just as the iPhone’s value has been optimised by opening up the iPhone platform to a legion apps, so government should do the same to optimise its value.
What “government as a platform” might look like in practice therefore, is a government opening itself up (from a data, policy and function perspective) and letting entrepreneurs build apps (real or virtual) to help facilitate the various functions of government in a more effective / efficient way.
As a way of explaining this, we’ve developed up an infographic to show how “government as a platform” could work from an open policy-making perspective – as this is our specific area of interest. As always, ideas and feedback are welcome . . .

Have blogged on similar from a local government perspective here http://localopolis.blogspot.com/2010/06/12-ipolis.html
Your graphic defintely wins the prize over my feeble effort tho