With a little help from my friends...

Well, I have, in fact, been working on the second half of my essay concerning the problem of celestial bodies in The Land of the Lost, but I've run into something of a roadblock and I hope that one of you can help point me in the right direction.

It's become fairly clear that this is an essay that needs some illustrations. I've Googled around for some that would fit the bill but haven't been able to find any, so it looks like I'm going to have to make them myself.

Does anyone know of an open source illustration program? I would prefer something that's easy to use (particularly since I have zero artistic talent). Ideally it would be something that would have a built-in ability to create illustrations of simple geometric structures, such as spheres, cylinders and toruses, with the ability to arbitrarily shade and label them.

If anyone knows of such a utility, please either email me or post a comment.

Thanks.