If you have a Core 2 Duo Macintosh, the built-in WLAN card is capable of networking using (draft 2) 802.11n. This capability can be unlocked via an update Apple distributes with the new AirPort Extreme Base Station. Or, they will sell it to you for $4.99. Why don't they give it away for free, say with Software Update? Because of the Sarbanes-Oxley Act (which was passed in the wake of the Enron scandal). iLounge quotes an Apple representative: "It's about accounting. Because of the Act, the company believes that if it sells a product, then later adds a feature to that product, it can be held liable for improper accounting if it recognizes revenue from the product at the time of sale, given that it hasn't finished delivering the product at that point."