This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
They're usually in the TOMCAT_HOME/logs directory, named localhost_access_log.2008-01-29.txt or something like that. If there aren't any, search the TOMCAT_HOME/config/server.xml file for "AccessLogValve". If it's commented out, comment it in and restart Tomcat.