You might have heard about this and came across some ads but in case not, here is the sales pitch:
National Geographic’s Great Nature Project is an initiative that inspires people to explore nature, take pictures of living things, and share their observations with the world at greatnatureproject.org. Anyone, anywhere in the world with access to a camera and the internet can contribute to the Great Nature Project at any time at greatnatureproject.org. From May 15 to 25, 2015, we especially encourage everyone to get outside and share photos of their encounters with plants, animals, and fungi as part of a global snapshot of biodiversity. The goal of the global snapshot is to document biodiversity all over the world during a specific window of time, repeated annually. Over time, this will provide data that can be used to answer scientific questions and provide useful information to decision-makers.
The Great Nature Project website is integrated with iNaturalist.org to record observations in a standardized way and allow other users to comment on and suggest species identifications for observations. Participants can also contribute to the global snapshot of biodiversity using mobile apps created by iNaturalist, including apps in Spanish.
You can think of the Great Nature Project as a global bioblitz and if for some reason you can't get outside to make observations and photos yourself, you can help identify what others saw by adding comments and identifications. The iNaturalist site has excellent tools for finding observations from places and taxa of interest. Some 454 000 photos have been uploaded so far from a lot of places around the globe. Keep them coming, still five more days to go.