Want to integrate charts into your webapp? Check out XChart.
Here's another nano-blog that will hopefully help someone solve a Tomcat error that I was dealing with today:
java.lang.NoSuchMethodException: org.apache.catalina.deploy.WebXml addServlet
The problem was that I was deploying catalina.jar within my .war file. Once I fixed up my build file to not include the catalina.jar file in the .war file, the error went away.