Elephind is a search engine for digitized historical newspapers. Currently, users are able to search 14 different source libraries (including the Library of Congress’ Chronicling America project), 1000+ titles, and over 1 million newspapers. Papers range in date from 1803 to 2012, so genealogists might find it especially helpful.
Thanks to Mary Seratt and Hillary Pesson for passing this along!
dynastree is a site that allows users to create their own family trees. This could be very helpful for children who need to do a genealogy project. There is also a great tool that will map the distribution of a particular surname in the U.S. A free registration is required to build a family tree, but the mapping tool can be used without a registration.