Phantom riding glitch

The Phantom Riding Glitch is a glitch can be performed in the Campaigns of both Halo 2 and Halo 3. It allows the player to travel within a Phantom. However, the player will invariably die, either by falling off or when the Phantom flies into a kill barrier.

Halo 2

Outskirts

Riding a Phantom is easy in Outskirts. You should have the Sputnik Skull activated. Simply:

Drive a Ghost through the level until you get to the beginning of the tunnel.
Kill all enemies and allies,.
Shoot the Phantom's turrets off with a Rocket Launcher.
It will look at you, and follow you if you move.
Jump onto the top of the tunnel; to do that simply grenade jump up, or jump on top of a Warthog, then jump up.
Jump on top of the Phantom, and it will eventually fly away, taking you with it.

Metropolis

You can also do this on Metropolis. To ride a Phantom on the bridge, do what is shown in this video. 200px|right

You can also ride on a Phantom by hijacking a Banshee and doing the same procedure that you would do to get the Scarab Gun.

Do the Banshee glitch.
Jump on top of a Phantom.
Enjoy the ride!

Quarantine Zone

It is possible to ride the Phantom that follows you in Quarantine Zone. To do this, have the Sputnik Skull activated. When you get onto the elevator, go to the back and quickly grenade jump. If you land correctly, you will stay on the Phantom. However, after a while, the Phantom will speed up and you will fall to your death.

Halo 3

200px|right In the campaign level Crow's Nest, you can ride on of the Phantoms and it will take you out of the map.

Jump on to one of the yellow clamps inside the hanger where you save a few Marines.
When the Phantom comes jump on top of it and grab one of the Plasma Cannons. This is easier if you place a Deployable Cover on of the clamps.
Leave the turret while pressing back on the analog stick and jump
When you hit the invisible wall, you will be pushed towards the middle of the Phantom. When this happens, get back onto the Plasma Cannon.
The Phantom will take you out of the map without getting you killed by the death barrier.

Trivia

You're also able to take a Phantom ride out of the map Tsavo Highway.
In Theater, in Crow's Nest, you can travel towards the Covenant ship in the distance. You'll find that the other half of the ship is missing.
You have the ability to flip the Phantom once it crashes near the rocks. This is similar to riding the pelican in the Halo 2 level Metropolis. Once it lands, you can flip it by pressing X.
This is also possible to do on the level The Covenant; see Disappearing on The Covenant (Level).