In the upcoming 5.0 release (coming within weeks), we have developed a new project state called "Draft" mode. This new feature will allow you to create a new project and assign people without giving them visibility.
Last week on September 12, 2012, my company, PIEmatrix, sponsored the IIL Global Summit on Leadership and Strategic Project Management organized by International Institute for Learning, Inc. (IIL) and New York University (NYU). In collaboration with IIL and Dr. Harold Kerzner, I was able to convert a great white paper by Dr. Kerzner called Project Health Checks into a set of actionable steps to execute inside the PIEmatrix application. We made this executable project free for all attendees