Brand Channel has compiled a list of "product placement" awards for movies. Apple, of course, has seen a huge rise in placements over the past 7 years.
When looking back between 2001-2003, Apple appeared in about 20% of all number one films. This percentage increased to 45% in 2005-2006 and is up to 50% in 2008. They acknowledge that even this 50% figure is deceptively low, however, since some movies (such as Indiana Jones) might have no opportunity due to its setting or time period. If you eliminate these movies, Apple appears in an impressive 67% of number one 2008 movies.