There is a Hidden Mickey on Toy Story Midway Mania at the loading dock for the ride.  If you look at the wall on the backside of the loading dock you will see a three toy story characters in circles.  The circle with Jessie makes the head while the circles with Bullseye and Rex make the ears.

Below is a picture of the Toy Story Mania Hidden Mickey formed from Jessie, Bullseye, and Rex.

As you ride Monsters Inc at Disney’s California Adventure pay attention to the control panel toward the end of the ride.

There will be all sorts of buttons, levers, and switches.  Towards the center of the control panel you will see a turn dial and two circular gadgets above it that form a classic Hidden Mickey.

Below is a picture of the control panel on the Monsters Inc ride with the hidden mickey.

Inside the building of the Monsters Inc ride at Disney’s California Adventure there is a poster on the wall that says "Monstropolis" with a picture of a yellow cab. 

If you look at the headlights of the cab you will notice a classic upside-down hidden mickey.

Below is a picture of the Monsters Inc hidden mickey.

In the Disneyland entrance area there are personalized stones with peoples names on them. 

Some of these stones have a bell and if you look carefully the ringer of the bell forms a classic hidden mickey.

Here is a picture of the personalized stone bell ringer hidden mickey.

There is a hidden mickey inside of the Main Street USA Penny arcade. 

First find the Pinocchio puppet game where you can control Pinocchio as a dancing puppet. 

If you look under the words "make him dance" you will see a classic hidden mickey.

Below are some pictures of the Pinocchio game inside of the Penny Arcade that has the hidden mickey.

As you walk along Main Street USA there is a door that says Disneyland Casting Agency.

If you go up close to the door there are two classic hidden mickeys.  One hidden mickey is on the top and one hidden mickey is on the bottom of the glass portion of the door.

Both hidden mickeys are formed by the decorative border of the sign.

When you enter the Main Street Cinema look at the step the lead up the platform in the center of the room.  There will be classic hidden mickeys on each of the three steps.

Each step has 2 hidden mickeys formed by lights that are used to light up the steps.

Below are a couple of pictures of the hidden mickey lights in the Main Street Cinema.

If you go to the fruit cart on Main Street USA you will see a hidden mickey below the cart.  The classic hidden mickey is formed by the green steel bars below the cart.

This may not be visible from all angles so you may have to circle around the cart and squat down to see it.  This one is a true hidden mickey.

Here is a picture of the fruit cart hidden mickey, look between the two wheels.

Inside the Blue Ribbon Bakery if you go the consession stand there is a painting on the wall that has a cow and a basket full of fruit.

If you look at the fruit basket there is a large yellow fruit and two green limes next to it.  This forms a sideways classic hidden mickey.

I personally am not sure if this is a legitimate hidden mickey, but this one is listed in the hidden mickey book.

Below is a picture of the painting with the hidden mickey.

The Gibson Girl Ice Cream Parlor is located on Main Street USA.  Besides having really good ice cream and waffle cones they also have a hidden mickey in one of their lamps.  The lamp is located near the back and is hanging above a dining area.  The hidden mickey is formed by the large jewel and the two small jewels above it.  If you stand directly under the lamp you can see a better hidden mickey tan looking from further back.  I’m still unsure myself if this is was meant to be a hidden mickey or not, but this one is in the Hidden Mickey Book.  You be the judge.

Here’s a few pictures of the lamp with the hidden mickeys: