Cheat Mode
To bring up the console, type "~" while playing. Type "sv_cheats 1" in the console to activate cheat mode. Then type any of the codes below: 

Code Result 
god God Mode 
noclip No Clipping 
undying 999 Armor, 999 Health 
map brig Hidden Level 
give # Give Item # (See Below) 


Give Items
Phaser
Tetryon Disruptor
Compression Rifle
Scavenger Rifle
IMOD (infinity modulator)
Tricorder
Health
Ammo
All