The Tiki Room was the first use of audio-animatronics in Disneyland.
Lincoln from Great Moments with Mr. Lincoln was first seen at the '64 World's Fair, then moved to Disneyland as the first human audioanimatronic. That later led to the animatronics seen in attractions like Pirates.
When you're walking down the queue on Indy, push the pole in the spike room.
Also in Indy's queue, when you enter the show room (with the slides), above you is a sign from the Eeyore parking lot (hard to see without both knowing where to look and a flashlight). That's because where you're standing was once the Eeyore parking lot.
On Tarzan's Treehouse, there are three things (that I know of) that remain from Swiss Family -- the first is the "watch thy head" label on a low beam. Second is the "Swissapolka" music playing in the Professor's work area at the bottom. Third is the little elephant also in that area.
The Haunted Mansion stood up but empty for several years before it finally opened to the public.
When riding Splash Mountain, while you're going around outside, listen for a snoring sound coming from Brer Bear's hole. That sound used to be the snoring of a bear for simple atmosphere when Critter Country was known as Bear Country.
I believe this is where this one is -- in one of the two theaters of Country Bears, the littlest bear (who holds a teddy bear) wears a cub scout uniform. That was donated by a cub scout who thought the bear should have the right uniform.
People once used to be able to fish in the Rivers of America from Tom Sawyer's Island.
The mill on TSI is a real working mill, and at one time they used to have it open so you could watch grain being crushed.
The Columbia is a scale duplicate of the first American ship to sail around the world. There's a museum inside the ship where you can see how the captain and crew lived.
On Thunder Mountain, the little village at the queue and end, and the rainbow caverns inside, are both remnants from an earlier train ride that used to be in the same place.
On Casey Jr. train, the open cars are actually refurbished seats from the carousel.
As you're coming around Matterhorn Way (?? -- the path to Fantasyland around the castle by way of the Matterhorn and Alice) -- look for the footprint of the Yeti. Lined up pretty much between that and Ariel's grotto is a vine-covered green concrete block. This is where the Montsano (sp?) House of the Future used to stand and is all that remains in the park of that futuristic structure. Which, by the way, had to be dismantled by hand because the wrecking ball just bounced off of it -- the house was made of plastic.
I'll stop there to leave tips for others to give
-Rajah
cdrtrisal@aol.com
(Links will return when I find a new place to host the sites)