Cameron Kaiser is a recovering database administrator and programmer who unwisely got an MD instead and now works as a county health physician in Southern California. He drives old United States highways, maintains old Commodore and Apple computers, and relentlessly implements old information technologies on his "$50 Wal-Mart server rack" in his rapidly disappearing spare time. He has used Macs since 1987 except for a brief stint we shall not talk about.
Option-Click AirPort Menu for Network Details
If you hold down the Option key while clicking the AirPort menu in Mac OS X 10.5 Leopard, you'll see not just the names of nearby Wi-Fi networks, but additional details about the selected network. Details include the MAC address of the network, the channel used by the base station, the signal strength (a negative number; the closer to zero it is, the stronger the signal), and the transmit rate in megabits per second showing actual network throughput. If you hover the cursor over the name of a network to which you're not connected, a little yellow pop-up shows the signal strength and type of encryption.