ethernet - how low can I go?

[gboyce-qL0WqcyiFk9Wk0Htik3J/w at public.gmane.org (Gregory Boyce)]

On Thu, 21 Jan 2010, R. Luoma wrote:

> I thank everyone for the responses to my USB query.
> Several people had suggested using ethernet,
> so I now have another question.
>
> Can I communicate via a cross-over cable between
> two computers at the ethernet packet level
> (specifically, without the TCP/UDP and IP lavels)
> using some set of linux drives?

Communicate how?  What sort of data do you expect to be traveling across 
the line?  Console, storage, something else?