I recently bumped into this site:
ataricommunity.com/forums/sh … p?t=506748
It contains some VERY nice skybox cubemaps and textures, and I just HAVE to tell you about.
The skyboxes are cubemaps, so ready to be used in Panda3D.
The only thing: these are TGA images. You have to convert them to jpg/png using any image program (like gThumb will do).
The topic also contains a tutorial how to make these. (scroll a bit down)
Please note that I did not make these awesome textures myself.