johnwasser:
PIND = 0x10; // Toggle Pin 4 (Port D bit 4)
PIND = 0x10; // Toggle Pin 4 back (Port D bit 4)
2 clocks faster should b this pulse: 
PORTD = 1<<4;
PORTD = 0;
EDIT: oops - its not faster... but it makes sure that the pulse goes into the right direction... 