I am creating a pricing program. I need to calculate the amounts according to the current tax list in the US (in various places).
I want to have a button 'Update taxes' in the administrative settings of the application, so when the user clicks it, it should download from somewhere the active tax amounts.
So I actually want to have a function decimal GetTax(string zip).
Does anyone knows about a free downloadable xml, or RSS accessible or even a website that I can crawle in and get this info from?