TCP Optimizer - SpeedGuide.net - The Broadband Guide. Cable modems, DSL, Wireless, Network security. Free speed tweaks and TCP/IP tools for optimizing system performance.
NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
Throttled Pro - Throttled Pro optimizes your internet connection and provides QoS (Quality of Service) to Mac OS X.
FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
Ashampoo Internet Accelerator - Ashampoo Internet Accelerator is an internet connection optimizer and booster that allows you to tune your connection settings.
NetTraffic - Essential network bandwidth monitor.