This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Some of this information is available through the manager web app. Since that is based on JMX (I think), it should be possible to connect to Tomcat with a JMX client and retrieve that information: Monitoring Tomcat