Note! This project is now an official Drupal project. You may download it by going here: http://drupal.org/project/shell
Are you using an inexpensive (or just plain limited) web host, and don't have access to a proper shell? You know if only you could pull up putty, you could perform some operation in half the time it will take you in cpanel or some FTP client. If this sounds familiar, then you should check out my latest Drupal 6 module, Shell.
Shell is a web-based Ajaxy pseudo shell which gives you most of the commands of your linux/unix server. This will not work for Windows servers. It works by passing whatever you type through PHP and directly to the server, then shows you the response. If you are comfortable using putty (or any other shell) then you will feel right at home with this module. It even gives you a tab-autocomplete like a real shell.