Having watched the classic Sullivan's Travels (for the umpteenth time) tonight on TCM it reminded me of the far reaching influence of Walt Disney. This 1941 Paramount Pictures film features scenes from the 1934 Walt Disney cartoon - Playful Pluto - starring Mickey Mouse and Pluto [one of the last B/W cartoons Disney made * ].
This film also provided the title for Touchstone Pictures' O Brother,Where Art Thou? from the Coen Brothers in 2000.
The only more recent usage I could recall was in Tom Hanks' 1996 feature film directorial debut, That Thing You Do!, where he featured the Matterhorn and Mickey himself!
Can you think of any other Disney non-Disney film cameos?