Movie location hunting can be great fun. If you are a Dirty Harry fan then you are made up in SF (there is a great site that tells you where all the scenes were filmed - google it if interested). Also if you are in LA / Hollywood there is a place you can visit to see the locations being used for filming that day (it can be a great waste of time).
I also had fun driving round LA looking for places I knew from songs (I remember finding the Miracle Mile and 'Sunset & Vine'). I took this to extremes when spending some time in Flordia when I realised I was driving down "Ocean Boulevard", safe to say that the current occupents of 461 did not want to indulge me with the afformetioned web site (though they were extremely polite about it).
Of course not everyone is a geeky as me.
lots of stuff has been filmed all over CA
for example: TV serise Tour of Duty, part was filmed in Hawaii and part was filmed around stockton and the delta - we have areas that have canals and rice paddies that can look like Nam.
Film: Coast to coast with Robert Blake and Dyan Cannon, Stockton was supposed to be Kansas CIty, it was downtown stockton, i had a walkthru in the background when i was about 19.
Film: Dirty Larry and Crazy Mary filmed in part around Lockford CA me and my mom and some friends watched a sceen filmed and the setup for other parts of the film.
American Grafitii and AM G II where filmed near Bakersfield CA and another town in the valley.
Animal House was filmed in part on the campus of a private University in Stockton University Of the Pacific - very old and looks like some east coast location.