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)
Set Per-Folder Views in the Finder
Tired of navigating to a particular folder and having to switch to List View every time? With Finder in Leopard, you can set viewing preference for each individual folder. Just navigate to it, and set the view the way you want (Column, List, Icon, or Cover Flow). Then choose View > Show View Options (Command-J) and in the window that appears, select the Always Open In... checkbox.