This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
Most enterprise level web servers / application servers natively provide such statistics. There are ways you could do such on your own via custom code, but it would be a pretty involved subject for a discussion forum like this. You might try doing some google searches on the subject. Also some of the better Servlet/JSP books out there might have a discussion on the subject. You may want to spend the afternoon at a good bookstore and flip through some books looking for ideas.