I've converted the second octree tutorial from http://www.gametutorials.com. It features frustum culling to eliminate nodes that are out of sight of the camera.
Grab the conversion over at my site: http://www.alistairkeys.co.uk/download/octree2.zip (173K)
(You need the DX headers since I used DirectInput for the input handling. Grab the headers from http://www.crazyentertainment.net if you don't have them.
Also, I've recently got around to finishing an exe for my Coolscale effect: it's here (17K).
I'll get around to finishing some of the tutorials soon (i.e., the already posted-but-not-finished one on non-VCL DirectDraw and the hidden one on timing (it's available, but you have to be 'special' to find it since it's not linked on my site anywhere)).