I did a Bing search for Hollywood conservatives 2012, and turned up this list of articles:
http://www.bing.com/search?FORM=WLETDF&PC=WLEM&q=hollywood+conservatives+2012&src=IE-SearchBox
If you vary the search (maybe omit 2012) you might find others.
But, of course, those who have come out for McCain or Romney may or may not be truly conservative. Probably what you want is to turn up a good number of names, and then research them further.
Thanks Cicero.