http://stuff.mit.edu/~lockername/
allow you to access the www subdirectory of the locker lockername. This will work with activity lockers, and home directories. For example, http://stuff.mit.edu/~tep/ or http://stuff.mit.edu/~bdclub/
http://stuff.mit.edu/~username/
where username is your username. For example: http://stuff.mit.edu/~mkgray/, or http://stuff.mit.edu/~rei/.
More detailed instructions on creating a home page is available at the How to put your home page on the web page.
http://web.mit.edu/lockername/
which allows you to access the top level of the lockername locker. In order to access the stuff subdirectory, you need to do http://web.mit.edu/lockername/www.