This 2nd-cycle gull was photographed in in the Coastal Plain near Houston and Galveston, Texas on April 26, 2006; I feel that it has some GWGU in it, and might possibly be a "pure" GWGU (at the darker end of what would be acceptable) - compare it to these birds:
http://www.birdinfo.com/A_Images_G/Glaucous-wingedGull_0089.html
http://www.birdinfo.com/A_Images_G/Glaucous-wingedGull_0014.html
http://www.birdinfo.com/A_Images_G/Glaucous-wingedGull_0017.html
http://www.nawwal.org/~mrgoff/photojournal/2005/fallwin/12-11p05gull.html
http://www.birdinfo.com/A_Images_G/Glaucous-wingedGull_0066.html - obviously not the same age, but compare the head/bill structure
:
NOTE the pink orbital ring - a color unique to GWGU:
