There have been several threads here on that subject.
However, I'll tell you the answer. The easiest way is to install Blanks from Cydia.
You can also create icons for any app or webclip that you would like to be there, just invisible. Use any existing icon as a template, make it one solid color, and make that color transparent. Rename the icon to match the app or webclip. Turn off icon labels to make it truly hidden.