NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
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.
FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
NetTraffic - Essential network bandwidth monitor.
NetCrunch Tools - Our free network tools offer ping scanning, SNMP scanning, port and network service scanning, and more.