I´ve been using chainsaw to remotely monitor an application that use log4j. I´m wondering if there are better ways to do it, or perhaps another logging framework.
There is nothing wrong with chainsaw, it is good. If you need something more, look at the log4j appenders. If you read all of the documentation with log4j you will see that the appenders can send logs to email, cell phones.....
We have built some JMX beans (the ones that come with log4j are not very friendly) that can display/scan/truncate/copy log files. As WolfmanDragon pointed out, you can use custom appenders to send your log messages to other destinations. Combined with a filter, you can send log4j error messages to a management application using JMX notifications, etc.
If you have absolutely massive amount of logging over many machines, you can use something like Splunk.
There are quite a few Java logging tools out there (see a list at Java-logging.com), so it really depends on your specific needs. For real-time monitoring, log files or remote logging to a log server, you might want to take a look at our Java logging tool SmartInspect.