If you're not familiar with Hindu names, this is a cool toy-- it tells the gender of names. I used to work in a university, and professors were always emailing me asking if the student they were meeting with was male or female. I should have directed them here!
Hindu Name Guesser
I think it works by analyzing the last letter or so of a name, and then using naming conventions to guess the gender. Of course, the first name I entered was "Aditya," which is the name of a dude I know. I always thought it would be beautiful on a girl... and the name guesser told me it was a female name. Were Aditya's parents hoping he was a girl, or is this the exception to the rule? Just for kicks, I typed in "Susan" and it told me it was a male name. I guess most Sanskrit-based names ending in N are for guys (like Narayan, Naveen etc.)
If you're not into Hindu names, check out the Baby Name Guesser. This tool searches the web and delivers results based on the findings. This site also has sone fun toys, like the Alter Ego Finder, which gives you a name of an "alter ego" by finding names with similar popularity and gender. The one it came up with for me was Cecilia Hillman, which is super creepy, because I was once engaged to a dude with the last name Hillman, and I always planned on naming my first daughter Cecilia. Cecilia Hillman was the name of our fictional kid.