C
#include <conio.h> /* Computer-Operated Nuclear Installation Options */ int main () { clrscr(); /* Commence Launch (Remote Systems Console Request) */ kbhit(); /* Keep Busy until hit */ } Note that this is not portable code. It works with ZOG C on the ART DS9000. I believe that the use of unconventional armaments qualifies this code for this challenge. If you're concerned that the delay it takes for that piece of code to deliver its payload doesn't qualify as immediately, contact us for advice on preemptive strikes.
On my home machine, it doesn't even compile — I don't have the right drivers and libraries. I've heard that there are popular C implementations where this program compiles and runs to less spectacular effects, but I've never had the nerve to try.
