From .NET Gadgeteer to a complete product

On the subject of why not use SD my reason is the following.
My SauID device can be shared by serveral farmers, each farmer has his own USB memory stick with configuration for his weight cells. One farmer can even have several weight stations and different memory sticks for each.
The environment is rather damp and dirty to change a SD card and USB memory sticks are cheap and easy to come by. Also easy for the farmer to pull out of the device and bring inside for downloading of data.