Better Idea
Go down to BestBuy and find one of those Linksys Bridges (not sure if thats the correct word, but it has an uplink port for internet and an external antanne port).
Then, on ebay, get a good antanne (not omnidirectional). They will run about 70 dollars.
This will take a crap on the thing that apple has right now. You have to use it with THAT antanne, while the rest of the world uses a regular ext. antanne port.