Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
PortsMonitor - PortsMonitor is a system utility for monitoring system TCP/IP network connections by application...
Fping (open source) - fping is a program to send ICMP echo probes to network hosts, similar to ping, but much better performing when pinging multiple hosts.
Proc Net Monitor - SecurityXploded is an Infosec Research Organization offering 200+ FREE Security/Password Recovery Tools, latest Research Articles and FREE Training on Reversing/Malware Analysis
Open Nettest - Open Nettest is a platform for collecting, processing and visualizing data related QoS and QoE.
CurrPorts - CurrPorts displays the list of all currently opened TCP/IP and UDP ports on your local computer.