This document discusses using social media to measure and filter science. It defines altmetrics as the creation and study of new metrics based on social web data to analyze and inform scholarship. An example study looked at blogging in chemistry. Current status includes academic work on usage metrics and altmetrics workshops and collections. Tools to measure altmetrics include those from PLOS, Mendeley, and Total Impact. Many questions remain around what impact is being measured and how to determine what population the metrics apply to. In conclusion, this area is just starting and may take 20 years to gain acceptance similarly to bibliometrics.