Get some extra equipment by going to the the Multiplayer 'Main' menu and selecting the 'Enter Code' option. Then input the following codes without the quotes to get the corresponding kit.

Unlock QBU88 Recon Kit (Sniper Rifle):
Enter the code 'your3mynextt4rget'.

Unlock the M60 Support Kit (Machine Gun):
Enter the code 'try4ndrunf0rcov3r'.

Unlock the Uzi Special Ops Kit (Machine Gun:
Enter the code 'cov3r1ngthecorn3r'.

These are earned in Multiplayer mode by completing the indicated task.

Unlock Destruction Site Wildcard:
Destroy 50 objects in a round.

Unlock Dueces are Wild Wildcard:
Kill 2 enemies of each kit in a round.

Unlock Five of a Kind Wildcard:
Destroy 5 vehicles of the same kind in a round.

Unlock Snake Eyes Wildcard:
Get 11 kills as 2 different classes in a round.

Unlock Staying Dry Wildcard:
With a sea vehicle get 2 seconds air time in a round.

Unlock Airtime Wildcard:
In a land vehicle get 2 seconds air time in a round.

Unlock Straight Flush Wildcard:
Destroy 1 vehicle of each kind in a round.

Unlock Full House Wildcard:
Destroy 3+2 vehicles of the same kind in a round.

Unlock Gunslinger Wildcard:
In Global get 80 kills with a handgun.

Unlock Santa's Litle Helper Wildcard:
Get 10 Kill Assists Points in a round.

Unlock Headshots Wildcard:
Get 20 kills from headshots in a round.

Unlock Squad Avenger Card Wildcard:
In Global get 100 Avenger Points avenging squad members.

Unlock Parashooter Wildcard:
Get 4 road kills with any air vehicle in a round.

Unlock Cab Driver Wildcard:
Spend 5 minutes in a round as a driver in a vehicle with passengers.

Unlock 1 On 1 Land Wildcard:
Destroy 1 land vehicle of the same kind without assistance in a round.

Unlock 1 On 1 Sea Wildcard:
Destroy one sea vehicle of the same kind without assistance in a round.

Unlock 1 On 1 Air Wildcard:
Destroy an air vehicle of the same kind without assistance in a round.

Unlock Chopper Chopper Kills Wildcard:
Destroy 5 air vehicles in a round.

Unlock Dead Eye Headshots Wildcard:
In Global get 100 headshots with any sniper rifle.

Unlock Squad Wild Card Wildcard:
Get 1 Squad Member trophy per squad member in a round.

Unlock Strike Wildcard:
Kill 10 enemies at the same time in a round.

Unlock Tank Buster Wildcard:
Destroy 5 tanks in a round.

Unlock Three Of A Kind Wildcard:
Destroy 3 vehicles of the same kind in a round.

Unlock Armor Buster Wildcard:
Destroy 5 armored vehicles in a round.

Unlock Savior Trophies Wildcard:
In Global collect 50x Savior Trophies.

Unlock Avenger Trophies Wildcard:
In Global collect 50x Avenger Trophies.

Unlock Beat the House Wildcard:
Get 15 grenade kills in a round.

Unlock 2 Pair Wildcard:
Get 2 of any 2 trophies in a round.

Unlock Full Deck Wildcard:
Get 52 total kills in a round.

Save time looking for items and weapons by accessing the map and looking for 'X's as these indicate their location. Also search near the 'X's as sometimes there will be gold pickup spots there.

Get the following weapons in your arsenal by completing the indicated task.

Unlock QBU-88 Sniper Rifle:
Unlocked through a unique code which was provided if the game was pre-ordered before June 23rd, 2008.

Unlock Uzi:
Download the 'Battlefield: Bad Company' demo version and then select the 'Quick Match' option. Then play a ranked match and get over 23,000 EXP to reach Rank 4.

Unlock USAS-12 Semi-Automatic Shotgun:
When you view your multiplayer stats online this weapon will be available the next time you sign into the game.

Unlock F2000 Assault Rifle:
Register your old Battlefield games at http://www.veteran.battlefield.com/

Unlock M60:
Visit the website findallfive.com and select the 'Join the Battlefield Community' option and sign up with Electronic Arts. When you then register for the 'Battlefield: Bad Company e-mail newsletter' you will receive a unique code by e-mail which will enable you to unlock this destructive weapon.