As far as I'm aware, the only way to do it is using JavaScript as suggested above. That would make sense, given that it is a client action.
Of course the other option is "File -> Print" which is much more reliable than client-side JavaScript.
You could probably do something with Active X but that would obviously limit your audience.
The choice of whether to use OpenACS on the server side is completely different from how you print the pages on the client side.