Moving Out

As with the main game, there is a hidden item in each of the 13 levels. You need to put it into the moving van before putting in the last item so that it counts. Here are the locations and ways to get them.

1. Sandy Shores
All the way to the left, past the jacuzzi, hidden by the palm leafs

2. Relaxing Rapids
Down in the South, by a bunch of coolers behind the house, sitting on a table.

3. McGeyser Falls Visitor Center
To the bottom left, beneath the Geyser, hiding under some leafs.

4. Crate Uncle's Campsite
Bottom left by the palm tree.

5. Forgotten Pirate Parley
Sitting on a pole by the ship. Use the whale to propell yourself and grab it while flying by.

6. Crashed Cargo Clearing
On the ledge to the left of the rope bridge. Jump down and throw it up, as you can't make the jump.

7. Mysterious Pathway
By the Waterfall to the right, on a ledge. Jump and grab.

8. Temple of the Windy
Blow away the duck on the column on the top floor to the north, the tape falls from the ceiling.

9. A Very Windy Puzzle
On top of the Pillar by the start.
There is a blue gem located on a pillar to the top left in the water. Blow down all gems so that the bridges appear to get to the items. Then blow away the blue gem and the pillar will drop (thanks jj6y)

10. The Temple of the Sacred Splash
Bottom Right. Drag 2 rafts to make a bridge and grab it.

11. The 36th Chamber of Cranks
In front of the truck, by the crank, is a scuba tank leaning against a wall. Take it, through it against the wall and re-grab it to fly up that wall and you'll find the tape hiding under the leafs on that ledge.

12. Mountain Goats Maze
Top left by the canoe, inside the right most pillar. Let a goat destroy it.

13. The Greatest Haul
On top of north spinning fan near the end (thanks Racknore).
You can use the fan to blow it to the end, I carried it though before blowing the gems to the next checkpoint just to be safe.

The text guide is really good and correct. In case you prefer a visual video guide, I have made a short location guide for all 13 levels.
00:00 - Sandy Shores
00:21 - Relaxing Rapids
00:35 - Mcgeyser Falls Visitor Center
00:50 - Crate uncles campsite
01:06 - Forgotten Pirate Parley
01:27 - Crashed Cargo Clearing
01:47 - Mysterious Pathway
02:10 - Temple of the Windy
02:36 - A Very Windy Puzzle
03:20 - Temple of the Sacred Splash
04:14 - The 36th Chamber of Cranks
04:47 - Mountain Goat Maze
05:21 - The Greatest Haul