Version: (using KDE 4.2.0) OS: Linux Installed from: Fedora RPMs When the menu bar is turned off (to save real estate) it should be available via right-clicking the konsole window.
In KDE-4.7, you can use keyboard shortcut to activate the menubar, even when it is currently hidden. See comment #10 in bug #154755. IMHO, this is more convenience than using mouse, since your hands are more likely on the keyboard when using konsole.