Well, if you need to crack a remote computer password then yes, use brutus from http://www.hoobie.net or go to http://www.milw0rm.com and they will crack it for you, or use ophcrack from http://www.ophcrack.com and then there is another great tool that you can use from http://www.oxid.it, then there is a site with lots of tools for download at http://www.elhacker.net.
all of them are really easy to use.