Tell them ahead of time that you'll be celebrating a special occasion during your visit and was wondering if they could put you in a special room. An anniversary, Graduation, Job Promotion, Birthday, First Visit to California, etc. I'm sure you can think of something and it doesn't even have to be completely true, although it would be nice if it were!
I'm not naïve -- I know what people do and say to get things in life, but that doesn't mean we will be encouraging it here.