There is no x86 binary demo version of Qtopia 1.4.0, however the previous version, 1.3.1 still makes an excellent demonstration.
The Linux/x86 demo works both on the Linux framebuffer and under X11 (using the Qt Virtual Framebuffer).
If you have the Linux framebuffer configured (16 or 32 bits per pixel) and you start the demo from the console, the Qtopia will use the framebuffer.