This is a very useful command if you are using subversion for version tracking. I just found out about the -u flag last week and I am loving it. It tells you exactly how an svn update would affect your working copy. This way you can decide whether you want to update to trunk with confidence. Previously there were times when I would update to the latest version only to realize that merging my code would take a little time, now I run this beforehand and decide whether to proceed right now or wait till I have more time. Enjoy 🙂