Upon DE's suggestion, I have modified the spreadsheet.<br/><br/>Everyone with the link can edit it, and everybody will see it. There is a "File history" in the menu that allows to see what has been changed and revert to an earlier version if needed.<br/><br/>The link is: https://docs.google.com/spreadsheet/ccc?key=0AvbE0kAR4hvxdFZaTXdfV0I3NGdoVEpRVUdfYWc2UXc