3D texture example or tutorial

Can anyone point me towards a tutorial or example code of doing image processing using the 3D texture buffer on a GPU? I have found a few papers concerning this, but no code samples to help get me up and running. Also, the papers that I have read refer to using an ATI card, and I have an NVidia Quadro FX 500. Thanx.

You can access our Visualization 2003 tutorial slides here: http://www.vis.uni-stuttgart.de/vis03_tutorial/

Our Open Source volume renderer OpenQVis is available here: http://openqvis.sourceforge.net/

ATI also has a small tutorial for a shell-based volume renderer here: http://www.ati.com/developer/sdk/RADEONSDK/Html/Tutorials/RADEON3DTexturing.html