I feel obliged to share my feelings on a long dead thread. It seems that primary inspiration in the Pacific Northwest could've been none other than Humboldt County, California. Home to the coast redwood the tallest trees in the world, which are featured rather prominently in opening title sequence in the Foster's yard. Humboldt County's small town atmosphere, cultural idiosyncrasies, proximity to both Hollywood and the ocean makes it the number one candidate for a permanent location if there ever was one. However Imposter's has proven that the location of the entire town is not static as it seemed to saunter its way towards the Canadian Border. That downgrades the entire County as simply a very possible, and probable inspiration.
Also if this wasn't the inspiration for the house, or one of the primary inspirations, I'll eat my hat.
http://upload.wikimedia.org/wikipedi...California.jpg
I mean right down to the signage.