Networking tool.

Hey, can anyone here give me an idea on what to use/how to kill dead connections which just won't die? I've got a nifty newsreader type prog designed mostly to D/L huge amounts of attachments, but if I need to close it out for a while and I come back later to use it the program's conections are still running, but not doing anything. So I can't start back up again. A tool like netstat or something GUI based would be nice just so long as I can see connection info so I'll know which connections to kill.

Gee thanks
-Ben