National grid to lat long conversion

[Carl Drinkwater | 29degrees]

> I have a load of British National Grid references that I want to
> convert to decimal degrees so I can create a google KML file. Does
> anyone know of a module to do this?

If there isn't a module available, you could roll your own.  The  
equations are to be found at :

   http://www.ordnancesurvey.co.uk/oswebsite/gps/docs/ 
convertingcoordinatesEN.pdf

They shouldn't be too hard to Pythonise.

Regards,
Carl.