The University of California, San Diego Data Mining Competition lets you test you data mining skills on a real world dataset.
The goal is to predict if a person is a potential customer. They have two data sets: a raw dataset with has some 300 variables per person and the transformed dataset has some 2400 variables per person. Using all this data about a person, you must predict if he is interested in buying things from you.
The last date for submission of your results is 30th September.
The competition home page: http://mill.ucsd.edu/

