Is there a simple ethernet splitter?

[Josef Lowder]

.
On Tue, 15 May 2007 23:19, Jon M. Hanson wrote
> Josef Lowder wrote:
> >On my 2-Wire modem/router, there is a single ethernet 
> >port that I have my main computer plugged into, and I 
> >have two other computers in our home that connect via 
> >wireless cards.  Now, I've just added another computer 
> >that I'd like to connect via the ethernet port, if 
> >possible. 
> >
> >Is there such a thing as a simple "splitter" that would 
> >allow me to plug in two computers into a single ethernet 
> >port on my 2-Wire modem/router? 
> >
> >
> That's known as a switch or hub. There's a little more to it than 
> just tapping into wires.

So what do I need to make this work? 
How complicated (and how costly) is it? 
Where do I get whatever device I need?