google map with UK postcode polygons, coloured as Choropleth/ Themantic map?

I've a SQLServer 2008 database containing names, addresses and postcodes plus lat/ long. I have a google map with an outline "boundary" polygon drawn on it, and then the data scattered across it.

What I need to do next is to switch that to a "heat map"/ Choropleth. Googling around the implementations I can so don't look too pretty and don't "know about" uk postcode boundaries.

So I'm thinking that I will need to draw my own postcode area polygons, and then colour them with my own heat map colours. I can see how to do that "the hard way". I already have the ability to GROUP BY postcode, so the frequencies are easy; drawing the boundaries is a bit of graft with the mouse. Alternatively I could opt for a square grid, which would require more server compute but less polygon drawing.

The free Code-Point® Open database has what I think are the centroids of the post code areas; irrelevant as I need the borders (I already know which person is in which post code

Finally to the questions:

1. Does anyone know of a data source for UK post code boundaries? Fortunately I only need to code a single city at a time, so I can draw them by hand if necessary, but obviously if they're already coded somewhere that would save me graft. I guess I'm looking preferably for data, but if I c开发者_开发技巧an't find that I'll need a map I can hand-copy.
2. Arethere any examples of this out there? I'm happy to re-invent the wheel, but not if I can steal it first.

If you are a member of a UK academic institution you can get postcode boundaries from the UKBorders project. The boundaries may be available to non-academics, so have a browse on the Edina [http://edina.ac.uk/ukborders/] site and see...

What level of postcodes are you after? Area, sector, district, or full unit postcodes? http://en.wikipedia.org/wiki/UK_postcode