Demos:
Joat's Demos
Demo of using both Screens at once
Download the demo here. To run this demo, you will need a passthrough or other mechanism that redirects ARM7 execution to the GBA port, and a GBA flash card. Place the file on the flash card and boot it. It will then copy the true arm7 and arm9 programs to the correct memory regions and start the demo.
For more information about my passthrough, see here and here.
Dovoto's Demos
Video of Dovoto's first demo using both screens. Frame buffer on main display and Backgrounds and sprites on secondary display. There is a video of it in action at http://ds.ninjaskillz.org/
Picture of first hardware rendered poly.
Pics of my current 3D cube demo on Firefly's yet to be released emulator.
Demos will be more current on:
http://www.drunkencoders.com/ds/
DesktopMa's Demos
http://auby.no