Here's a tip for the arachnophobes. You dont need a special bug killer for spiders. Use Hornet or Wasp killer. That way, you can remain a safe distance away.
For those NOT afraid of spiders, but want to give them a "taste of their own medicine" (the spiders, not the arachnophobes), Use a quality spray adhesive, for example 3M Super 90, and spray the little bastards with that, and enjoy knowing they will be forever glued to their webs, and serve as the "Head on a Stick" for future 8 legged terrorists.