Use the following passwords:
NOJIRI: unlock the Strain card
SHINTA: unlock the Gijin-san card
KONAMI: unlock the Reaction Block card
VIPER: unlock the Viper card
MIKA: unlock the Mika Slayton card
KAREN unlock the Karen Houjou card
JEHUTY: unlock the Jehuty card
XM8: unlock the XM Eight card
SIGNT: unlock the Mr. Sigint card
SHRRR: to unlock the Sea Harrier card
DCY: unlock the Decoy Octopus card
MCCY: unlock the Roger McCoy card
HNMT: unlock the Reiko Hinomoto card
AYM: unlock the Kinoshita Ayumi card
MGR: unlock the Ishii Meguru card
NTM: unlock the Natsume Sano card
NEXTGEN: unlock the MGS4 card
SONOFSULLY: unlock the Jack card
SNAKE: unlock the Solid Snake MGS4 card
OTACON: unlock the Otacon MGS4 card
MK2: unlock the Metal Gear MK. II MGS4 card
RONALDSIU: unlock the Banana Peel card
GINORMOUSJ: unlock the Emma's Parrot card
GEKKO: unlock the Gekko
SMOKING: unlock the No Smoking card
THESPANIARD: unlock the Possessed Arm card
TOBIDACID: unlock the Solid Eye card