3D Textures (and gluScaleImage)

I have a question about 3 dimensional textures. There’s the convenient gluScaleImage function for making sure a 2D texture has the proper power of 2 width and height, is there anything out there that can do that with a 3D texture?

I’m curious because I have a chunk of 3D textures, and right now I’m manually slicing them up and displaying them as 2D textures, and I’d really like to be able to fiddle about with the 3D texture functions that are available in OpenGL, but none of my data matches the requirements for glTexImage3D (the 2^m width/height/depth one…).

Any pointers would be appreciated…