A vast room of poster presentations greeted thousands of scientists at the American Geophysical Union's annual autumn meeting, which started on 15 December 2008 in San Francisco, California. One of the posters stood out, writes Nature reporter Rex Dalton at In The Field (http://tinyurl.com/a4oe48), because it described an 'experimental hydrology wiki', or collaborative website for researchers in the field.

The website, http://www.experimental-hydrology.net, was created by Theresa Blume of the University of Potsdam in Germany and Llja Tromp-van Meerveld of Simon Fraser University in Burnaby, British Columbia, with the aim of sharing knowledge about established and new methods of experimental hydrology. As well as helping people to avoid reinventing the wheel when planning measurements, and enabling users to learn from others' mistakes, the wiki should assist researchers in choosing appropriate methodology and equipment.

All experimental hydrologists are invited to contribute to the website, either by writing or contributing to an article, or by answering questions at the site's help desk.