WiFi Stumbler is a free web-browser based tool from Meraki that allows you to find WiFi hotspots or wireless connections near to your PC. With the help of your PC’s or notebook Wi-Fi antenna it will scan local access nodes and provides information about nearby wireless networks.
On visiting WiFi Stumbler page, first it will scans for local wireless network and displays the result in a bar graph and list’s available networks. The graph shows number of visible SSIDs broadcasted in each channel and the results of access points shows SSID, MAC address, signal strength, manufacturer and even the kind of encryption they are using.
WiFi Stumbler will run on most of the browsers either on a PC (Windows XP, Vista, 7) or a Mac (Mac OS 10.5 (Leopard) or late) and it can be used even if your not connected to the Internet, but your browser must supports HTML5 offline mode (Firefox 3.5 and Chrome support HTML 5).
The only requirement to run WiFi Stumbler, is you must have Java installed in your PC.Check out http://meraki.com/tools/stumbler for more details and to try it out.