Q13:  Where can I get a copy of public-domain flight planning software
      and other good stuff on the net?

A:   Aviation data changes on a day-to-day basis.  Your best bet is to
     use the comprehensive flight planner which is available from GTE
     DUATS (see Q10).  GTE has a staff which maintains the database on
     a daily basis, and the flight planner is a thorough and complex
     piece of software.  It is also the only known flight planner which
     has been tested and approved by the FAA; this was done as part of
     the FAA-required DUATS review process.