Matthew's right, but instead of futzing with custom patch cables just get a two or four jack RJ-45 outlet and break out two unused pairs into the other jacks. You'll need to know which wires of course but the jacks aren't hard to wire. I did a 1-1 cable run for my parents (who'll never have more than 2 PC's) and I made the downstairs end crossover so they could use standard patch cables. This might vex the next owner of the house, but I really don't care. Just be sure to mark the outlets!

-Zeke