If you get a router, you can use both computers independently. If you buy a wifi router, you can use your laptop without cable, too.
(I'm sure internet connection sharing on directly connected computers would also work, but...)
If your laptop's wifi supports only B/G (not N), and you can afford this model, get this one:http://homestore.cisco.eu/store/ciscoeu/en_IE/pd/productID.241269400
There are cheaper ones, but the WRT54GL is a classic model, you won't regret buying it.