AWR - (Alpha Whiskey Romeo) Allah's Waiting Room. When engaged, [insurgents] have a tendency to flee to the same building (the AWR), at which point the troops radio in an air strike.
LPCs - Leather Personnel Carriers, or combat boots. Generally used when describing a mode of travel (ie. "we'll be taking our LPCs over to the range")
Big Chicken Dinner - Bad Conduct Discharge.
Chicken in a frypan - Specialist (E4) rank insignia, which has an eagle inside a shield.
First Lieutenant, Second Award - a Captain, so named because the insignia of grade consists of two parallel silver bars
Jesus Cruisers - Flip flops. See also Shower Shoes
Rock Eaters - Term used by troops during the Balkan missions to describe locals. It comes from the locals teeth decay, which was explained by saying that they ate rocks making their teeth fall out.
Three Men in a Boat - Stop, the Arabic letters making the word 'stop' appears to be three men sitting in a canoe.