SpeedOf.Me - SpeedOf.Me is an HTML5 Internet speed test. No Flash or Java needed!
Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
Fast.com - Quickly test your internet speed with this fast-loading speed test powered by Netflix.
SmokePing - Smokeping is a tool for measuring latency.
Speedtest.net - Test your Internet connection bandwidth to locations around the world with this interactive broadband speed test from Ookla
PingInfoView - PingInfoView is a small utility that allows you to easily ping multiple host names and IP addresses, and watch the result in one table.