FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
NetTraffic - Essential network bandwidth monitor.
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
NetBalancer - NetBalancer is a Windows application for local network traffic control and monitoring.
Network Activity Indicator - Network Activity Indicator displays the old 'two monitors' icon in Windows 7 that flashes blue to show network activity in the System Tray.