Beyond Compare should be added to your consulting tool belt
It is not very often that I recommend a tool that we don't make. :-) You will find a few if you search the archives, but maybe only one or two. This tool just saved my bacon in a HUGE way. You ever had an XML file and wondered what the differences were? Or how about two directories and trying to remember how your files are mashed together?
If you do, then check out Beyond Compare. It works on Source Code files, Batch Files, XML files, Windows Directories. It also do a pretty cool Directory to FTP Site check, which was uber handy for a new web site I am uploading where the FTP server was "unreliable." It did a killer job of automatically reconnecting and taking off where it left off.
For Microsoft folks reading this, you can check it out in the Site Licensed Area of ProductsWeb. For everybody else, check it out here. http://www.scootersoftware.com/moreinfo.php?c=features
The licensing price is awesome even for a site license for a small company. Once you start using it, you will spend weeks trying to figure out why you haven't been using it sooner. :-)
This is one of my favorite tools ever... It will one of your's too... :)