A program that monitors internet usage by program on the mac?

I’m not exactly clear what you mean by usage..

If you’re interested in how much time you’re spending on the internet, and running different programs, then you should check RescueTime. It’s free, powerful, and works well on OS X.

Actually, I would love to know that. Thanks.

I was thinking more along the lines of what programs are using bandwith and how much.

I should have been more clear.

Little Snitch will show you which applications and processes are making network connections, and rank them by activity. There is a meter that shows relative incoming and outgoing activity, but it does not indicate how much data is being transferred.

iStat Menus will show you an average of how much date is flowing to and from your Mac.

I run both continuously.

excellent!! That is exactly what I want!
Thanks!