Baby Name Voyager is a very interesting tool that shows the trend of baby names. For expecting parents, especially those not growing up in USA, it is very helpful to see which names are popular and which might be outdated. For example, boy's names like Ethan and Owen are getting a lot of popularity, while names like Arthur and William are losing attractions.
For parents with older students, this is an ingenious tool to diaplay large amount of information in a way common people can understand and appreciate. It is simple, elegant and useful. Studying how it is done could be a satisfying math/computer science project.
The author, Martin Wattenberg, holds a PhD in Mathematics from the University of California at Berkeley. This shows how creative and fun mathematians can be.