http://home.eunet.no/~pnordahl/ntpasswd/bootdisk.html

Geez. How difficult is it to remove that final period?

This particular tool is one I use in class when students forget their password or it gets changed during wargames. It's pretty good and I like the fact that it works off of a floppy (yes, those things still exist). If you look you'll see instructions on how to remove a password for an AD as well as AD using Win2003.