I've also started homebrew GameBoy Advance development, and I've been surprised by how easy it is to get things up and running on the actual device. It's quite cool to say the least. Unfortunately, the GBA has no 3D hardware, and no 3D API, so after searching the net a bit I decided to learn and program my own 3D software rastizer. Progress for this has been ok. I've got Gouroud shading working correctly. However, my fill algorithm isn't quite correct, so I'm taking out a lot of time to fix that. Hopefully I'll make pictures of this soon.
Lastly, there was a GameDev gathering in London last week. It was quite fun to meet more of the people from the forums. I did take a few pictures (click for larger):
C J W and csarridge
phantom, Sandman and Superpig
phantom, Sandman(without camera) and Superpig
polly, Monder and MarkR
Clockwise starting at bottom left: Boruki, C J W, Superpig, Monder, polly, MarkR, Sandman, Phantom and csarridge with *PIES* in the middle.
Thanks to all of you for a great time, and I hope to do it again soon.
And also, me and my friend are currently writing a 3d rasterizer for PocketPC, so I look forward to seeing some shots of your GBA 3D rasterizer.