Michael really pulled the curtain back.
Two week ends ago "I", little ole me, added GFIC protection to my outside outlets. Total cost? Less than $3 (GFIC dual, ganged outlet, Home Depot) and about 45 minutes of reading the directions repeatedly and slowly. After all, I don't look good with 20 amps running through my body.
There is NO EXCUSE for not having outside circuits GFIC protected, unless of course you want to be a dangerouis charge in someone's life.
As others have noted.what is REQUIRED depends on when the house was constructed, local requirements and proper permitting. You wouldn't live in a house without locks on the front and back door, nor should you have a house without GFIC in potentially wet areas.