A couple of times, I actually went looking for some entry similar to Microsoft Windows Startup menu in the GNOME menu structures, but each time, I came up empty and frustrated.
Finally, I found out how, and I wrote it down. The following works for the GNOME Desktop 2.14.3 using the Debian Etch Linux distribution.
To configure GNOME to auto start an application on login,
-  Mouse to Desktop -> Preferences -> Sessions.
  
-  Click to select the Startup Programs Tab.
 
-  Click Add.
  
 
-  Enter the command, e.g., skype, and click OK.
 
 Note: You may need to enter the full path for the command, (e.g., /etc/bin/skype) if the command is not in the command path.
 
-  Click Close to exit Sessions dialog box.
 
