Remove Show Password

This is an easy one - here's how it's done:

1. Boot (or reboot if it is on) and press ESC when you see the option to enter the GRUB menu
2. Select "Normal Boot" from the grub menu (but don't press enter) and press the "e" key on your keyboard
3. Select the line in the box that begins with the word "initrd" and move the cursor to the end of the line. Backspace over the four letters "aufs" and replace them with "generic". Do not add any spaces.
4. Press "ctrl+x" on your keyboard to boot
5. Open a terminal (ctrl-alt-t) and type "sudo gedit /usr/share/nm-applet/ws-wpa-psk.ui". This will open the ui file for that part of the network manager applet, which is a simple xml file.
6. Select "Go to line" from the "Search" menu, and type 75, then press enter
7. You'll notice an xml block with "Sho_w password" in it. Underneath you'll see a property for "visible" that is set to "True". Change this to "False" and save the file. (See below)

Before

              <object class="GtkCheckButton" id="show_checkbutton_wpa">
                <property name="label" translatable="yes">Sho_w password</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">False</property>
                <property name="use_underline">True</property>
                <property name="draw_indicator">True</property>
              </object>

After

              <object class="GtkCheckButton" id="show_checkbutton_wpa">
                <property name="label" translatable="yes">Sho_w password</property>
                <property name="visible">False</property>
                <property name="can_focus">True</property>
                <property name="receives_default">False</property>
                <property name="use_underline">True</property>
                <property name="draw_indicator">True</property>
              </object>

Reboot, and the Show Password checkbox will no longer be visible in the wireless security settings.