For those who would like to do some GTK/Glade projects with Ruby, i hope these links will help you out.

http://www.micahcarrick.com/12-24-2007/gtk-glade-tutorial-part-1.html#Adding_Widgets_to_the_GtkWindow
http://xrob.wordpress.com/2007/04/20/creating-a-gui-application-using-glade-and-ruby/
http://www.perfectxml.com/syngress/ruby/Page2.asp.