iStumbler is an easy way to scan for information about the Wi-Fi environment around you, as well as see available Bluetooth devices, and what Bonjour services are available on the local network. The latest version, release 99, works only with Mac OS X 10.6.2 or later, adds support for the 5 GHz band used by 802.11a and 802.11n, and takes advantage of the coordinate-based location feature in Snow Leopard to allow GPS-like tracking as the application scans. (Free, donation requested, 1.1 MB)
Expose Shortcut for View All Windows
In Expose mode in Snow Leopard, press the Tab key to view all windows belonging to one application (equivalent to pressing F10 or Control-F3 on recent laptops). Press Tab again to switch between applications while remaining in Expose. You can also click an icon in the dock.