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)
Always Show Recipient In iChat
In iChat under Snow Leopard, choosing View > Always Show Recipient Bar puts a buddy's status message and color at the top of any iChat window. It can also be used to select among multiple open iChat logins you have to send a message to that buddy, or to select among multiple accounts you have registered in Address Book for that buddy.