The eastern United States is hunkering down for the arrival of Hurricane Sandy later this weekend. If you're in the storm's way and have a secure place to stay, consider taking part in a citizen-science effort to collect rainwater samples from the storm. Run by waterisotopes.org, it's a project to map the isotopic composition of the storm's water and gain insight into the internal processes of major storms. The page I linked to has a set of instructions and information about what the scientists hope to learn. But don't delay, because the best thing is a series of samples collected all the way through the storm's passage.