Send data through USB without connect device?

Well, after days of researching and testing with USB library i have a big question.

Is it posible to send data through usb cable without verify if the endpoint device is connected?

I have two develop boards: a BS2 Homework Board USB and a Netduino USB.

It is posible to send data to those devices???
Obviously a cheap way, that dont need to buy any external atachment

Thanks in advance
Regards