monitering

Is there any tool available that will let me monitor the source and destination of all Inbound and outbound traffic from my system ? And also how much of the bandwidth each programme accesing the internet is using? For example. suppose i am using Yahoo Messenger...is there any tool that will...

hi... i m using flashet,though it is one of best download manager ,but sometimes it doesnt moniters the downloading files.such files r downloaded by the internet explorer download manager which is not resumable.when i download some themes from these...