The Mathematics Genealogy Project, Mitch Keller Managing Director, has long been one of the favorite time wasters for mathematicians on the internet. Just type in the name of your teacher, advisor, or yourself, if you are a PhD, and you will be able to track back, through the advisor-student relationship, all the way until the records run out and probably find yourself admist such luminaries as Gauss, Bernoulli, and Leibniz. Well over at thatismathematics they have used the data from the Mathematics Genealogy Project to put together a brand new service: Mathematical Relationship Search. Just input the names of two mathematicians and voila, you could find out, like I did, that your advisor is the sixth cousin six times removed of Carl Frederich Gauss.