How about a material node to make quick & dirty normal maps out of texture files?

Normal maps can be made from 2d image files with effective results, but it seems like the only way to generate them is by using a photoshop plugin or third party program.
I had a ‘crazy’ idea, why not make a node within the material editor to convert regular texture files into those crazy, bumpy normal maps we love so much?
thanks for listening to my suggestion!