Yep, Xenon, thanks for the heads up, I forgot to mention that.
Indeed a hub will allow every computer on the local net to "sniff" every packet simply with setting the network card in promiscue mode.
With a switched network this becomes *a lot* more difficult. Therefor if you do not want that your room / house mates see what you are doing / what you are downloading ... get yourself a switch.

shame on me not to add this first.