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)
Using Expose within Spaces
To drag a file into an application that's running in another one of your Spaces, use Expose while in Spaces overview mode. First, press F8 to go into Spaces overview mode, then press F9 to Expose all application windows. Hover over the application window you want and wait a moment or press the Space bar, and both that space and that application come to the foreground, ready for you to drop the file.
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