Too lazy to call aunt Sue to find out more about your great-great-grandmother? Unable to track down your biological parents? Don’t fret. Ancestry.com is rolling out a new family-tree service built on DNA.  From the Wall Street Journal: “Companies crossing DNA-mapping technology with social networking are developing a brave new world in which samples of customers’ genes can be used to map family trees, find relationships people never knew they had, and identify adopted children’s biological parents.” No more secrets here.  Imagine how interesting school projects could become.  The service will cost 99 dollars, and “lets users compare some 700,000 points on their own genome with those of others in its database.”