You can also cut the cable and rewire it to be a crossover cable, or cut open the plastic and swap the specific wires. Just hold up the two ends, with the tab thingy away from you, side by side, and see if the order of the wires matches (orange to orange, green to green, etc.) If they do, its a straight cable, so either take it back and get a crossover, or modify it. If they dont, then its either a reverse-pair, rollover, or crossover cable (crossover is most likely, the average user wont come across the other ones).