Wireless N = more range, also faster for in-the-home stuff (and internet if you are lucky). You can get little USB dongles, expresscard / PCMCIA if your laptop has that, or replace the mini-pci card (you'll only get 150mbps instead of 300 due to lack of second antenna, but this is still an upgrade on wifi-G 54mbps).
Assuming you haven't got it already
