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)
Easily Change Firewall Settings in VirusBarrier X6
If you need different levels of protection on your laptop based on location, you can set up VirusBarrier X6's two-way firewall with multiple configurations. Whenever you change locations, switch easily to the firewall settings you want to use from the Intego menu, located in the menu bar. Make as many configurations as you want: for home, office, when you're on public Wi-Fi, and so on.