In the new NetBeans 6.7 we can easily change the font of the output window. We must right-click in the output window and we get a popup menu. We select the option Choose Font... and we get a dialog window where we can choose the font for the output window.
Changing the size of the font is also very easy. If we right-click in the output window we get a popup menu with the options Larger Font and Smaller Font. The default shortcut keys in Windows are Ctrl+Plus and Ctrl+Minus. So if we have a lot of text in the output window and we have good eyes we can make the font really small to get it all in one output window.