Apple last week released two security updates, version 1.1 of Security Update 2007-005 (see "Security Update 2007-005 Released," 2007-05-28) and Security Update (QuickTime 7.1.6). As of this writing, Apple had said nothing about what was fixed in the 1.1 version of Security Update 2007-005, but the QuickTime security update fixes two issues in QuickTime for Java that could result either in arbitrary code execution or disclosure of sensitive information. That sounds similar to the security fixes in QuickTime 7.1.6 itself from earlier this month, but it seems to be different (see "QuickTime, AirPort, Security Updates Released," 2007-05-07). In either case, both updates are likely worthwhile. Downloads for Security Update 2007-005 1.1 are available in PowerPC (15.7 MB) and Universal (29.2 MB) forms, and Security Update (QuickTime 7.1.6) is a 1.4 MB download. Or just use Software Update to get the appropriate version for your Mac.
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.