Forget answering, I just figured it out. When on a call the menu item "Loudspeaker" appears on the lower right portion of the screen. If you press the upper right soft key you will activate the loudspeaker. I didn't try it yet but I assume that if you press the same key again during the call it will deactivate the speaker.

Just received my 6030. I know it has a speaker phone but how do I activate it?