To connect two PCs together you need a [crossover cable][1], unless both PCs NIC support Auto-MDIX, in which case you can connect them using  a standard Ethernet cable.

The Pi's NIC supports Auto-MDIX, you should check if your laptop NIC supports that feature, or simply connect them using a Ethernet cable, if the link does not come up then it means you will need a crossover cable.


  [1]: http://en.wikipedia.org/wiki/Ethernet_crossover_cable