Not everybody is aware that the famous scientific journal Nature has started an editorial experiment on June 2006. Starting from that date all authors who submit their manuscript for reviewing can also decide whether they want their work to be publicly available to all readers on the Nature website for open reviewing: not only will readers be able to go through the manuscript but they are also invited to leave comment to the server. As of now 69 papers appeared on their website but only 37 comments were given in total: that makes far less than a comment per paper! Other websites exist where scientist can upload their work as preprint manuscript, the most famous being arxiv.org, well known amongst physicist. It is not unusual for a manuscript pre-published on arxiv to receive pages and pages of comments, sometimes including figures. The system of peer reviewing is universally considered as one the most powerful features of today’s science but its application is not seldomly debated.