Thanks Erel
Didn't try it but it should work.. What I need to know is (for production) to program a number of boards.. Say 100+ boards.. I don't think the methods above is practical. Remember the EPROM programmer with 8 sockets for 8 EPROM chips to be programmed at once..
Connect all your boards to a usb hub.
In a program Ask for active com ports then launch avrdude for each com Port. In net you can use System_IO_Ports_SerialPort_GetPortNames.