At our event in San Jose today (2/19/2005), someone brought up log4net. log4net is a convenient utility that can be used to output logging information, to practically any pre-defined target. For those of you PERL and JAVA programmers, we've had log4perl and log4j respectively, and log4net is very similar.
Have a go at : http://logging.apache.org/log4net/
One thing (of many things) I've particularly liked about the log4* is the different "levels" of logging information it provides.
Please realize that I am in no way endorsing or mandating the use, or the non-use, of this. It's an open-source project and comes as it comes. So, please use it at your discretion.