'End Point Scan', and 'Net Stumbler'

End Point Scan

Scan for devices connected to your network. Are you aware of all the devices that have been connected to your network, such as: USB sticks, CDs, floppies, smartphones, MP3 players, handhelds, iPods, digital cameras? As an administrator, do you know how many employees have been using or are using portable storage devices at the moment? Monitoring your network for these devices is not only time-consuming but nearly impossible to do manually. With GFI's free web utility EndPointScan you can actually check within minutes what devices are or have been connected to computers in your network and by whom .

http://www.endpointscan.com/

Net Stumbler

NetStumbler (also known as Network Stumbler) is a tool for Windows that facilitates detection of Wireless LANs using the 802.11b, 802.11a and 802.11g WLAN standards. It runs on Microsoft Windows 98 and above. A trimmed-down version called MiniStumbler is available for Windows CE. NetStumbler is commonly used for: Wardriving, Verifying network configurations, Finding locations with poor coverage in one’s WLAN, Detecting causes of wireless interference, Detecting unauthorized ("rogue") access points, Aiming directional antennas for long-haul WLAN links. This program is a MUST HAVE if you use Wireless Internet and want to know which wireless channel # to use in order to obtain the best WiFi reception in your home (and so it doesn't conflict with other WiFi signals in your neighborhood)!

http://www.netstumbler.com/downloads/