Here’s a bonus on top of a bonus: OS X 10.8 (Mountain Lion) adds a really useful “Wi-Fi” scan feature, buried inside a utility I didn’t know existed.
I wanted a Wi-Fi scan tool to show me a list of nearby wireless networks and strengths, so I could avoid interference from existing networks when placing and choosing a channel for a new access point, and verify the new access point is operating properly. A few years ago I did this with KisMAC, MacStumbler or iStumbler, but these utilities seem to have stopped working over time, either as a result of newer hardware or newer OSes.
Googling for new alternatives to these utilities, I found that Mountain Lion actually has this functionality built in. There’s a “Wi-Fi Diagnostics” app buried in /System/Library/CoreServices (where, annoyingly, Spotlight can’t find it and the Finder by default won’t show it); at launch it presents a very limited-looking wizard interface, but in the menubar the File:New command and command-N keyboard shortcut have been replaced by an unassuming “Network Utilities” command.
This brings up a “Network Utilities” window, not to be confused with
/Applications/Utilities/Network Utility.app, with a bunch of really useful utilities (which look like a strict superset of the old Network Utility, have a more modern UI and additional functionality, and except for the “Wi-Fi Scan” tab, have no reason to be restricted to Wi-Fi networks).
I only wish this thing were easier to find; it should probably replace the old
Network Utility app. I don’t remember seeing it mentioned in most what’s-new-and-why-to-upgrade articles about Mountain Lion. For me, it’s a pretty nice bonus to having upgraded and deserves wider mention.