It's not too difficult I would hope to implement a wrapper around the readers that allows them to read from a compressed file. The PDB archive was just switched to use gzipped .gz for their mmCIF and PDB formated coordinate lists.
Vi, Jedit, my own little program Wattos all have no problem doing it so can Pymol?
Cheers,
Jurgen
Good point!
this is implemented, ticket can be closed