Via Jerry Beck and Mark Evanier (that's two in a row for Mark, but this one is too good to pass up):
The home movie that the Barstow family took of their vacation in Disneyland in 1956 was recently given the honor of being named to the National Film Registry by the Library of Congress. This caught the attention of Steve Martin, who was eleven years old at the time the movie was shot and working at the park selling guidebooks (which I'd read about in Martin's autobiography, Born Standing Up). He spotted himself in the footage and contacted the filmmaker Robbins Bastow. If you watch the movie, you can see little Stevie Martin very briefly, described in this article.