The Random Comment Book by graphic designer James Obriant allows you to put words in people’s mouths (well, above their heads actually) without the need for pesky thinking or talking. Sez he:
STEP 1. SNEAK UP ON FRIEND
STEP 2. HOLD NINJA-LIKE ABOVE FRIENDS HEAD
STEP 3. EAT NACHOS (OPTIONAL)
LET THE RANDOMNESS BEGIN.