Network monitoring

Is there an easy-to-use, preferably free, program that will show me which processes are sending and receiving packets to/from the internet and how many packets each process is sending/receiving? I took a look at Wireshark, but I'd rather try something simpler.

I don't want to study to become a MCNE or do 2 years of post-doctoral research in IT; I just want to see which programs are engaging in internet traffic and how much traffic they're generating.

Windows XP Pro SP3 totally up-to-date
No hardware firewall yet
RASPPPoE on ADSL supposedly 1536 Kbps down/128 Kbps up
testmy.net performance ~1370 Kbps down/ ~96 Kbps up SOMETIMES

I have good reason to believe that my PC is free from malware.

 

Traffic rate is what I seek

Thank you very much for your quick reply, Steve. I'm looking for something that will show usage on the internet for each process in packets/second or Kbps. While CurrPorts is neat, especially when combined with IPNetInfo, I don't see how to determine how much internet traffic each process is responsible for. I'm trying to find out how my bandwidth is being used. Thanks again.