I`ve made a public album of X-RAY human (and few animal) skeletons. Feel free to browse. I`m going to expand this as time goes.
also I`ve made a CT scans album and I`ll be adding lots of images as well in future:
Both links are now added to my blog links.
This can help riggers to solve problem of correct joint placement in 3d character models, but also to understand the function of inner body structures and the reason for certain bone shape, position in human body and the flesh grown around them.