Sharing a broadband connection?

[johnnymac]

Hi, can anyone help here.

I have broadband which comes into a broadband router/modem. This has two connections, USB (which my flatmate uses for his MAC), and ethernet which I use. I want to be able to use the 2 computers I have on this ethernet connection. Can I buy a 'switch' or such to allow this, without the hassle of building a network, to save me from moving the cable from PC to PC as wished?

Joe