Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
Venmon - Compact size system resources monitoring utility and multi-ping tool for Windows
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.
TinyResMeter - TinyResMeter is a small tool that displays useful information about system resources in real time...
PingDoctor - PingDoctor is software that is considered to be the most powerful and easiest to use network route analyzer.
Mousotron - Mousotron is a mouse and keyboard activity monitor and keeps statistics of your mileage. It's like an odometer or tripometer for your mouse cursor.