Gufw - Gufw is an easy, intuitive way to manage your Linux firewall.
NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
NetLimiter - NetLimiter is an ultimate Internet traffic control and monitoring tool designed for Windows.
FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
Little Snitch - Little Snitch is a firewall application that monitors and controls outbound internet traffic.
NetTraffic - Essential network bandwidth monitor.