Monitor Your Network Activity with Networx
Networx is a free network monitoring tool that can be used to monitor incoming and outgoing traffic on selected network adapters and connections. You can monitor all your network connections or only selected ones.
The incoming and outgoing traffic is represented in the form of graph or you can also get it logged to a file so you can always check your daily, weekly, monthly statistics about your bandwidth consumption. You can even setup alerts to notify you when some strange activity happens, like when network is done or there is some heavy data flow which normally never happens. It comes with Speedometer which allows you to collect your download speed statistics. You can use it to solve your network problems or track your bandwidth usage. You can even set it to disconnect from the Internet when network activity exceeds a certain level. You can also perform network tests like ping and traceroute. It can also display a list of all the applications which are currently using the network connection.
It is free and works in Windows 2000, XP, 2003 and Vista.