Sorry if this seems more like a heads-up than an actual topic, but I thought this would help some gamer with lag in matches. And I’m hoping this isn’t the kind of post you want to put (I saw nothing in the guidelines saying you can’t put this).
I’ve been using HughesNet for about 3 months now (it’s satellite, and it’s the highest package), and throughout those three months I’ve had to suffer through horrible lag, but during that that time I figured out a few things; the good, the bad, and the ugly:
Bad:
A 2-3 second shot, melee, and grenade delay
Having to move very slowly on both foot and vehicles (crouch speed for foot, regular foot movement speed for vehicles)
Most armor effects skipping around when activated (save for hologram and sometimes invisibility)
Black screens popping up now and then, stopping you from playing while other may or may not be playing.
Disconnections (not too often though)
Good:
Grenades take a couple seconds to be thrown, but I learned that if you throw it and change where you are looking, the grenade will still go the direction you are facing, despite what direction you originally threw it. You can exploit this to use a plasma grenade and make sure it sticks your target.
Grenades can also be thrown after you die. If you throw a grenade right before you die, you… well, die, but wait a second and the grande will ‘fly’ out of your body and will land near it. This exploit got me the ‘Totally Worth It’ achievement pretty fast, and plus it’s a nice way to get rid of a teabagger. XD If your reticule was pointing at a target and the target is close (must be really close) then the grenade will fly at them, much like the first exploit I said.
It’s also possible to perform a showstopper against the opponent assassinating you with lag. If you make a strike that should kill your opponent, and they end up assassinating you, focus the center of the screen right on them from any angle. The game will register the shot, and will head the direction where the reticule would be (the center of the screen). However, there have been a few times when this didn’t work.
You can perform a foot-style walk-by with any weapon, although I always used the DMR. If you see an opponent coming you direction, take a headshot, and just keep moving. The shot will still register, even if he/she is behind you or you don’t even see them. This also works with melee.
Multi-kills are also easy with this (I call it shoot-and-aim instead of aim-and-shoot). That 1-2 second lag gives you time to hit one opponent and then give you time aim for the next, so you don’t have to worry about being too fast when aiming.
You might have heard of the rocket lunge in Halo 2; you can do this also if you zoom in fast enough and then immediately press the melee button to go flying across the map. Nice thing about it is that when you’re behind an opponent and you hold the melee button down while you are flying, you get a nice soft landing pad on their back, along with an assassination. There have been some times that this lag glitch did not work.
You can’t drive vehicles unless you are moving very slow, but you can still get around by being a passenger or gunner while somebody else is driving without worrying about any lag. Again, the ‘shoot and aim’ method works for vehicle weapons.
I would recommend playing Snipers or Swat, since both of them don’t take much fast movement and as fast reaction time. It’s nearly impossible to drive vehicles, but I learned you can still be in one if someone else is driving.
The ugly:
If you do happen to ignore the lag and drive anyways, stay away from steep slopes/hills, and rocks, unless you enjoy watching yourself being launched into the air and most likely plummet to your death. You may have seen this on videos; this is exactly why. It’s also possible that on Forge maps (such as Hemorrhage) you can end up flying out of the kill zone boundaries and onto a different area, such as the island.
If you don’t aim properly using the trick to stop your own assassination, you can end up killing yourself. I ended up doing this with a sniper rifle and got a suicide, and the sad part is that I got no yoink. 
(You did stop an assassination, after all).
If you do the zoom lunge and the opponent moves (and sometimes not), you’re looking at a fast splat against a surface.
I’d rather prefer no lag than any lag, but when you have to deal with it, you have a few ways to turn it around. I am still looking for any other exploits, and I’ll post any when I find them. My advice? Play Team Swat or Snipers, since they don’t take as fast of a reaction time as other modes. Score attack works perfectly fine, just as if you were playing a custom firefight game.
Other modes:
Infection might be worthwhile, but it’s nearly impossible to use the shotgun in it.
In BTB and invasion, keep a distance from the battlefield and make use of precision weapons. Being a gunner for a vehicle isn’t so bad either, as long as the driver doesn’t flip.
Objective is fairly easy since most players are focused on the goal. You can be support, or you can ignore the lag and go for the objectives.
Co-op Firefight is a definite no, unless it is two people on the same console. The lag in it is so horrible, it makes the game nearly impossible to play. Not only is there the regular shot delay, but there is also a movement delay on both foot and vehicle, making it extremely hard and frustrating just to get to the other side of a rock.
Grifball is difficult since you can hit an opponent but have to wait for the hit to register, while they can kill you right away.
As for the other modes, do the same as you would do for Invasion and BTB.
Satellite links always tend to have a natual delay, what with the whole beam to space and back through networks, through space again and back to your system 'n all.