The Baby Name Wizard's NameVoyager

If you appreciate the graphical display of information, this site is absolutely amazing. It requires the ability to run Java (free and already incorporated into most modern browsers).

The site is basically just a database of the popularity of a number of given names over the last 100 years. The width of a particular name's "band" is proportional to its popularity, with blue bands for boy's names and pink bands for girl's names. By typing a name into the site, you will see a graph of that name's popularity over the century. If you only type the first few letters of a name, you will see those names which start with those letters.

This description is boring. But the site is very cool. Go play...