The Application Event Log that is commented out in the app.config file。
allows you to write to the event log, for debug/error info, instead of writing a text file:
http://www.samspublishing.com/articles/article.asp?p=606221&seqNum=4&rl=1
Once you uncomment all you have to do is:
Application.Log.WriteEntry("Something disasterous happened in my app :)", TraceEventType.Information);
Before you had to use a component from the toolbox, this is now available straight out of the box in the my namespace