Several helpful third-party tools and utilities are available for log4j. Most of them are free and/or open source. For example, there are several Swing-based GUI applications that allow you to view and filter log messages dynamically, which is ideal for administrators in a production environment.
There are also several other types of appenders that other developers have created that might be helpful to you. You can find these third-party extensions in the log4j download area at http://logging.apache.org/log4j/docs/download.html. It's definitely worth the time to take a look and see what's there. The list of available extensions is constantly growing.