How to tell you are host...
	Ladder - Aim Time...
	Quicker Melee...
	Steam Achievements...

Press Tilde (`) or Shift + Tilde. If a Remote Console (or Rcon) shows up. Then you are the host. This is more noticeable with Shift + Tilde because it shows the entire killfeed from the round before.

Prior to climbing a ladder, press the melee button, and then begin to climb. If timed correctly (for example the ladder on Seatown), the character will no longer need to bring out his gun and therefore upon reaching the top of the ladder, the gun will already be brought out ready to fire. This can save time and may benefit in you getting a kill.

Remember you could melee faster with Akimbo USP .45s in Call of Duty: Modern Warfare 2? Well you can still do it in Call of Duty: Modern Warfare 3. Just equip USP Akimbo and use your knife, you will noticed that you will be pulling out your knife faster.

Achievement	How to unlock
50/50	Complete a Special Ops Mission Mode game with the same number of kills as your partner.
Arms Dealer	Buy all items from the Survival Weapon Armory.
Back Seat Driver	Track down Volk. Complete "Bag and Drag" on any difficulty.
Back in the Fight	Start the Single Player Campaign on any difficulty.
Bad First Date	Find the girl. Complete "Scorched Earth" on any difficulty.
Birdie	Kill 2 enemy helicopters without getting hit in a Special Ops Survival game.
Brag Rags	Earn 1 star in special ops mission mode.
Carpe Diem	Escape the mountain safe house. Complete "Persona Non Grata" on any difficulty.
City of Lights	Complete "Bag and Drag" and "Iron Lady" on Veteran difficulty.
Danger Close	Take down a chopper with an AC-130 smoke grenade in "Bag and Drag."
Danger Zone	Buy all items from the Survival Air Support Armory.
Defense Spending	Buy all items from the Survival Equipment Armory.
Diamond in the Rough	Rescue the Russian President. Complete "Down the Rabbit Hole" on any difficulty.
Flight Attendant	Kill all 5 enemies during the zero-g sequence in "Turbulence."
For Whom the Shell Tolls	Destroy all targets during the mortar sequence with only 4 shells in "Back on the Grid."
Frequent Flyer	Defend the Russian President. Complete "Turbulence" on any difficulty.
Get Rich or Die Trying	Have $50,000 current balance in a Special Ops Survival game.
I Live	Survive 1 wave in a Special Ops Survival game.
Informant	Collect 22 intel items.
Jack the Ripper	Melee 5 enemies in a row in Single Player or Special Ops.
Kill Box	Kill 20 enemies with the Chopper Gunner in a single run in "Return to Sender."
Ménage à Trois	Destroy 3 tanks with a single 105mm shot in "Iron lady."
Nein	Kill 9 enemies with a-10 strafing runs in "scorched earth."
No Assistance Required	Complete a Special Ops Mission Mode game on Hardened or Veteran with no player getting downed.
One Way Ticket	Make it to Westminster. Complete "Mind the Gap" on any difficulty.
Out of the Frying Pan...	Complete "Persona Non Grata", "Turbulence", and "Back on the Grid" on Veteran difficulty.
Overachiever	Earn 48 stars in special ops mission mode.
Payback	Complete "Mind the Gap", "Goalpost", and "Return to Sender" on Veteran difficulty.
Requiem	Escape the city. Complete "Blood Brothers" on any difficulty.
Sandstorm!	Assault the shipping company. Complete "Return to Sender" on any difficulty.
Scout Leader	Collect 46 intel items.
Serrated Edge	Finish a Juggernaut with a knife in Special Ops.
Storm the Castle	Discover makarov's next move. complete "stronghold" on any difficulty.
Strike!	Kill 5 enemies with a single grenade in Single Player or Special Ops.
Survivor	Reach Wave 10 in each mission of Special Ops Survival mode.
Tactician	Earn 1 star in each mission of special ops mission mode.
The Best of the Best	Complete the campaign on Hardened or Veteran difficulty.
The Big Apple	Complete "Black Tuesday" and "Hunter Killer" on Veteran difficulty.
The Darkest Hour	Complete "Eye of the Storm", "Blood Brothers", and "Stronghold" on Veteran difficulty.
This Is My Boomstick	Kill 30 enemies with the xm25 in "black tuesday."
This is the End	Complete "Scorched Earth", "Down the Rabbit Hole", and "Dust to Dust" on Veteran difficulty.
Too Big to Fail	Destroy the Jamming Tower. Complete "Black Tuesday" on any difficulty.
Unstoppable	Reach Wave 15 in each mission of Special Ops Survival mode.
Up to No Good	Infiltrate the village. Complete "Back on the Grid" on any difficulty.
Vive la Révolution!	Reach the church. Complete "Eye of the Storm" on any difficulty.
We'll Always Have Paris	Escape Paris with Volk. Complete "Iron Lady" on any difficulty.
Welcome to WW3	Save the US Vice President. Complete "Goalpost" on any difficulty.
Wet Work	Take back New York Harbor. Complete "Hunter Killer" on any difficulty.
What Goes Up...	Destroy all the choppers with only the UGV's grenade launcher in "Persona Non Grata."
Who Dares Wins	Complete the campaign on any difficulty.