Explosive jumping

Grenade Jumping
Grenade jumping, or occasionally known as grenade hopping, is a trick where the player throws a Grenade onto the ground and jumps as it goes off, using the force of the grenade to propel them forward. It is usually done with the Plasma Grenade as the sticking nature is easier to work with. You can get to higher places with this trick. If the player has got the Sputnik skull, grenade jumping will be twice as effective but note that skulls only take effect in campaign and grenade jumping will be normal in any type of multiplayer game.

This can also be done by aiming down with a Rocket Launcher, then shoot and jump at the same time or, if you have an Overshield, both a grenade and a rocket.

(to do this on Xbox Live you need to be host)

Bomb-Box Super-Jump
This is a neat little trick that works best in the multiplayer level Zanzibar. What you need is:

Any kind of gun (except Rocket Launcher and Brute Shot) Those Bomb-Boxes that explode when you shoot or hit them A grenade if you wish An Overshield And yourself!

First, push one or two of the Bombs (no more than two, you will die with three) and jump on top of one of them. Then jump and about half a second after you tap the jump button, shoot the Boxes, and you will fly up above everyone! This is useful to get up to high places for sniping, or to kill another sniper. You can also hide some boxes around a corner so when the opponent appears you can give them a nasty surprise.

Explosive Jumping on Zanzibar
On the beach on Zanzibar there is a ramp-like piece of debris (the ideal game type to try this is on Assault, although it will work on any game type), take the bomb and crouch walk at the bottom of the debris while looking just ahead of your own feet, this may take a few tries. Another player will need to drive the hog back a bit and then gain a lot of speed in order to ram you (the bomb carrier). You will be propelled the length of Zanzibar and land on the roof of the base. Remain crouching or you will show up on the motion detector. Be aware of the fan: it is quite easy to smack into it and lose the advantage. If you make it onto the roof, wait for your team to covertly join you. From there you have the element of surprise and should be able to gain the upper hand as there is actually a hole in the roof through which your bomb carrier can enter the base through.

This can also be done with Capture the Flag or Assault on Coagulation using the rocks where the Shotgun can be found. This is less risky if the person in the Warthog has the highest level of handicap on as they will do less damage to the player being rammed.