By default, the USB key drive is usually named something like "NO NAME," so change it to something more convenient - short, no spaces, and note that the name must be uppercase. As an example, let's name the key drive BOB. The actual unix location of key drive BOB is /Volumes. Apache won't serve anything from there, so you need to go into your Sites directory and create a unix-style symbolic link to BOB. Do not create a Mac alias, because it's not the same thing. In Terminal.app, enter the following commands (don't type the % - it represents your unix prompt):
% cd Sites
% ln -s /Volumes/BOB BOB
Next you have to edit your Apache user config file, located in /etc/httpd/users. For now, let's say your shortname is xyz. The default xyz.conf file in that directory looks something like this:
<Directory "/Users/xyz/Sites/">
Options Indexes MultiViews
AllowOverride None
Order allow,deny
Allow from all
</Directory>
So, still in Terminal.app, type the following commands (don't type the ## or anything after them; that's just a comment to explain what's happening with each command):
% cd /etc/httpd/users ## Change into the directory
% sudo cp xyz.conf xyz.conf.original ## Make a backup of your config file
% sudo vim xyz.conf ## Use vim (or your editor of choice)
Edit your config file to look like this, (replace xyz with your short username):
<Directory "/Users/xyz/Sites/">
Options Indexes MultiViews FollowSymLinks
AllowOverride None
Order allow,deny
Allow from all
</Directory>
<Directory "/Users/xyz/Sites/BOB">
Options Indexes MultiViews
AllowOverride None
Order allow,deny
Allow from all
</Directory>
After saving and closing your config file, restart Apache by typing sudo apachectl graceful. Now you can access the key drive in a browser at this URL (replace xyz with your short username, of course):
http://127.0.0.1/~xyz/BOB/
If you have PHP enabled and running, you can test PHP locally as well. Hooray!

