Xirrus Wi-Fi Monitor
This gadget is great for avid Wi-Fi users or technicians. The main display (see Figure 2) gives you the details of the network you're currently connected to, such as the SSID, channel, signal, local IP address, and client MAC address.
It also features a unique listing of nearby wireless networks. It's in a radar form, with the higher signal networks appearing closer to the middle and the lower signal networks on the outer edges.
You can click Show Details for many more details. You'll see a more traditional listing of the Wi-Fi networks (see Figure 3), specifying the 802.11 standard and encryption type, signal/RSSI in dBm, and MAC address of the AP. You'll also find a list of packet statistics for advanced troubleshooting and a glossary of networking terms for reference.