USB comms.

I was wondering if there was a way to communicate from one Arduino (ex. Uno) to another via USB???

Have you seen a cable that has two ends of the kind that connect to the Arduino?

have you ever created a USB master? it is not pretty. Stick with serial.

JJellison:
I was wondering if there was a way to communicate from one Arduino (ex. Uno) to another via USB???

NO.

Why do you want to ?

...R

The DUE has a native USB port. You can stick mouse & keyboards in.

mistergreen:
The DUE has a native USB port. You can stick mouse & keyboards in.

And? That does not help with Arduino-Arduino communication.