can 2 Arduinos communicate via USB ?

Gerald Trost wrote:
> I would connect 2 Arduino Nano to a USB HUB on my computer.
> Is there a way the 2 Arduinos could communicate in this configuration
> via the existing USB cables ?
No, because the hub is not able to route any information directly from 
one of the end points to the other. You must communicate between the 
arduinos over the PC: one sends its data to the PC, where a piece of 
softwar eis running that puts that data over to the other arduino.

Gerald Trost wrote:
> Is there a way the 2 Arduinos could communicate
> in this  configuration via the existing USB cables ?

 short and sweet:

 NO.