Useful network utilities
I used this yesterday to identify speed issues at a customer’s home. Turned out there were four routers on channel 6 (his was one, moved to 7), four on channel 11 and two on channel 1, all of which I could connect to in his home office. It also showed me signal strength so I could adjust the location of his wireless adapter to get the best connection.
http://www.passmark.com/products/wirelessmonitor.htm (30 day free trial)
WirelessMon is a software tool that allows users to monitor the status of wireless WiFi adapter(s) and gather information about nearby wireless access points and hot spots in real time.
Overlook Fing (Freeware)
Network discovery tool
iPhone, iPod Touch, iPad Apps:
Overlook Fing (Free)
IP Network Scanner Lite (only shows first five devices, paid app is $5.00)
System Scope Lite (Full version is $4.99)
Ping Scope Lite (Full version is $.99)
Not quite Network Utilities
These are not specifically "Network Utilities", but I have found them to be very useful.