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)
Find Your Mac's Serial Number
Want to check your Mac's serial number quickly and easily? Select About This Mac from the Apple menu, and click on the text directly below "Mac OS X" that reads "Version 10.x.x." Click once and you'll get a build number which is more specific information about the software. Click twice, and you'll get your Mac's serial number.
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