-Take out a Scorpion Tank in Multiplayer with a Pistol-so funny a walking dude can kill a guy in a heavily armed tank. Use the scope and fire away. It takes about six shots if your aim is good.
-Warthog Jumping. In co-op, where it is much easier to do, get to an area with several grenades on the ground-namely a dropship crash site or the crash site in the Silent Cartographer with the second Warthog you meet. Gather grenades and kill each other while standing on the same pile of grenades until you have a huge number of grenades on the ground.Then have a player who has one grenade and throw it. Stand on top of the pile or drive a Warthog in there and fly HIGH.in single player, its much more annoying. You must gather grenades by killing Marines, who often don't carry them with them very much.
-If you can get a Marine to drop some grenades, then go back to a checkpoint so it saves. Keep on doing this until you get enough grenades to trigger an explosion big enough to launch yourself or a Warthog high in the air.
-Use the same technique with a Scorpion Tank...or a Ghost. I have yet to do it with a Banshee or Wraith, but Ghosts and Scorpions are absolutely hilarious.
-Get on top of the Silent Cartographer. You can use the Warthog Jumping technique to jump the Warthog up, but if you want to get there by yourself, there's a much easier way, and different than what most people tell you to do.
In the area where the Hunters are, up the path and near that structure which leads to Jackals and a group of enemies, the first Hunters you meet in the level, kill one of the Hunters. Then lead the next Hunter to the wall which is next to an "island." This is where you want to jump. This is the wall next to the path you went up, on the left side when you came up the path the first time, near that last rock before the Hunter's area. Lead the Hunter to this area by staying close and letting it swipe at you, but don't let it walk back to its original spot. When you get here, let the Hunter melee you, press A to jump, and it'll do a "mega swipe" which propells you into the air. Once you get a "mega swipe" try to land on the top of the wall, in which eventually you'll make it. Feel free to walk around on top of the Silent Cartographer level!
Attach a Plasma Grenade to a Jackal or an Elite-both hard to do because the Jackal has a shield which means you'll have to either be behind it or aim for its feet-I often have lucky shots where it somehow gets stuck to them-Elites strafe a lot, so try to "lead" your throw. If you can land it on them, they'll often wipe out Grunts and Jackals too, as they often hang out near Elites.
-Snipe enemies before a Covenant dropship lands-see the Covenant dropship section for more information.
-Make enemies want to go back in their dropship-see the Covenant dropship
section for more information.
-Throw a grenade into the ocean in the Silent Cartographer. When the grenade explodes, it's realistic and awesome.
-Drive the Warthog into the water in the Silent Cartographer. If you keep on driving, you will eventually reach a spot where you can't continue.
-Fire a rocket into the water. Use the scope and watch until it explodes. However, you may want to kill yourself after this, as you don't want to waste ammo for a rocket launcher.
-Get the hidden Banshee in AoTcR(assault on the control room)-The area after you first get the Scorpion Tank with the two Wraiths[one is on that hard to reach ledge you can't get up without of course a Banshee],an ice pond, jackals, elites, and grunts manning shade guns, as well as hunters wating for you...u get the picture..anyway, head out to that small hilly platform before the ice pond and locate a small platform high up pretty much behind you. You'll need to get to the edge of the hill to see it. Zoom in with your Sniper Rifle and aim for the middle of the bottom of the platform. Then, without moving your crosshair, press Y to switch to your Rocket launcher(you need the RL, and its easier if you have the sniper rifle), and fire. Hopefully a Banshee will fall off the platform for you to take through pretty much the whole level(you can even fly to the bridges and land, then go through the level normally with no enemies until you get to a locked door which you can't go through. Trust me, there's no point, I tried and had to go all the way back to the Banshee). Fly up to that pesky Wraith and locate the center tree(on the left) that's floating above the ground. It's quite funny. Anyway, if you miss shooting the Banshee, try again. If you can see it fly in the air due to the impact, and if you see where it lands(still on the platform), guess where it is and keep on firing. If you run out of rockets, you can backtrack to the crashed dropship and get more. If you are completely out of rockets, kill yourself. Hopefully your Marines haven't cleared out the area(very very small chance of this). Just don't pass the ice pond without the Banshee or the Banshee will be taken by an Elite.For more information, check out Dark Helmet's site for a video on this!
-This isn't really something you can do, but once in that area with the Banshee(mentioned above), the Wraith somehow fell off its high little spot and was lobbing mortars at me from the ground..Odd...
-Again something that you can't really do, it was a glitch-in Silent Cartographer, when you go to the place where Cortana shouts "Don't let them lock the doors!" I killed everyone and let the doors locked, then shot at the Swordsman Elite through the doors small glass window. He disappeared, and when I got the door open, there was a Plasma Pistol hanging in the doorway which was just floating there...I shot it with the Assault Rifle and it fell...Also in that cutscene where the swordsman elite walks through the door after you have shut down the security, he was standing with the Plasma Pistol floating through him..weird..usually I just skip this place though, I go directly to the security override place after clearing out all the fricking Elites in the hallway above the security place.

-Flip a Wraith Tank over. If you can resist shooting a Wraith, jump in a Scorpion(in AoTcR) or a Banshee(a Scorpion is easier), and keep ramming the Wraith until it flips. Keep turning your tank and try to back the Wraith against a wall or ledge so it flips. This may take a while, so keep your patience and keep ramming the Wraith. Eventually it will flip if your patience was good enough, and you will see the Elite fall out. DO NOT USE THE CANNON ON THE ELITE. It will most likely hit the Wraith and destroy it as well. Instead, use the machine gun or ram the Elite, then get out of the Scorpion. If you approach the Wraith, you will see a prompt which reads "Press X to flip Wraith." No, you cannot get inside the Wraith, but it's fun flipping it. It took one guy seven times to flip a Wraith over! It's only taken me once or twice..too bad..

-Skip the annoying Halo level light bridge FMV sequence(in other words, cutscene). Throw a plasma grenade when you're at the control panel, then activate it(Press X). Now you won't have to watch that annoying cutscene.

-I call this Warthog Ramming. In any multiplayer map which allows vehicles(or in co-op), line yourselves up(preferably on flat ground, so near the bases in Blood Gulch is a good idea, Sidewinder not good because the ice makes it hard to control), "hit the gas," and charge, crashing head on. One of you will go flying and probably land the jump. If you even barely miss, you often don't get air. This is funny and entertaining.

-Target practice. In multiplayer, allow all vehicles in a map(sidewinder or BG). Have Rocket Launchers. Have a player be in a Ghost or a Warthog(Ghost is better), and another with the RL. The player in the Ghost will get air off a Scorpion Tank, and the player with the RL will try to shoot the Ghost out of the air. If you can hit that spinning Ghost, your aim is excellent. This improves your accuracy and ability to lead targets, especially with the RL.

-Kill the Elite before it gets to the Wraith in the first phase of Two Betrayals. Head down the right side of the pyramid like structure until you get to the bottom(not on the snow though). You'll see an Elite hopping into the Wraith. Using your Sniper Rifle(which you get at the very top of the structure-climb up the ramp after exiting the hangar-like rooms), kill it and you won't have to worry about the Wraith. When you get to the Banshee, you can flip it over and over again without its strafing around a lot.

Here's a link from HBO-http://halo.bungie.org/tipsntricks/display.html?collection=xbill.wraithsnipe

-Just something to do if you're bored..Okay I suggest you go to Blood Gulch. You need a map that supports vehicles, and sidewinder does as well, but the ice can get in the way of this. You must have Scorpion Tanks, a ghost, and a Warthog to do this "stunt." You can do this with one player or two. Line up the scorpion tanks side by side, then put a Ghost in front of one of them. Get your Warthog, and back up, speeding up and going off the Ghost for some insane air. I have done many funny things with this-I have got onto one of the bases, twisted in midair and gone over both of the scorpions and landed, and got thrown in the air, landed on the scorpions and got bounced around before I finally got thrown off. This is very funny, and doesn't take too long, even if you have one player.