If you have Poser  5 or 6, open it, go to "Windows" and "Python Scripts" and "Utilities" and you will see "compress files" and "uncompress files".   Pick the "uncompress files", browse to your folder that has the files you want to uncompress, and let it run.  Your .obz files will be inflated to .obj ones.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi