IIS 5.0 on Windows2000 Server…..

I am using Windows2000 Advanced Server IIS Server. How do can I look at a real-time view of Traffic on my website? In other words, I know IIS keeps a log file, but is there a way to view it in real-time? I’m want to know how many people are on my website at a given time. ( kinda’ like how ServU does for FTP) Anyone Know anything?