Update Jan 16, 2008: Look what was lurking in the background when I first found this bird - bottom of page...
This presumed Adult Vega Gull (Larus [argentatus] vegae) was photographed February 21, 2007 in the Coastal Plain near Houston and Galveston, Texas, Texas:
Update Jan 16, 2008: This was the first photo I took of the above bird (arrowed on the left) - I did not notice an even more interesting gull in the background, arrowed on the right:
This bird is slightly darker than the one above - towards the dark end for a Vega and approaching the tone of Atlantic Yellow-legged Gull or the palest of LBBGs; note the bright pink legs and rather rounded head with strong nape streaking: