I have a three inch PAL monitor, left over from another project. So I just connected it to the Pi, made a little change in /boot/config.txt and started it up. When the Pi booting, I could see the boot messages, and when it had finished booting, I ran startx to start up xwindows. And I got the xwindows gui on the three inch monitor. I can even navigate it using the mouse. But I have to admit, it's not easy to read what's there!