Hi, the approx. P wave shadow zone would be from
103 to 140 degrees from the quake location.  So, you would be in the
shadow zone of any quake that is approx 103 to 140 degrees from you. 
Any mapping program that would draw a circle around your location at
103 and 140 degrees will work.



Here is a link to more info on the P wave shadow zone:

http://earthquake.usgs.gov/learning/glossary.php?termID=170&alpha=S



The usgs also draws a world map for quakes of mag 5 and above with the
shadow zone marked.



start here:

http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/quakes_big.php



When you get to the list, click on the
   Date and Time   link of any given quake.

Click on the    Scientific & Technical    tab

Find and click the    Theoretical P-Wave Travel Times    link

  enjoy,

  

  Stephen

  PSN Station #55

  near Pilot Hill Ca USA

  38.828N  120.979W





GPayton wrote:

  
  
  
  
Gentlemen,
  
 
  
Is there a software package or applet that allows you insert
YOUR geographical location (Lat. & Long.) and output exactly where
on the globe YOUR P wave and S wave shadow zones would be?
  
 
  
Thanks,
  
Jerry