Grumpy_Mike:
Another technique is to put a pin high, do the code and put it low, using port manipulation.
Will the "port manipulation" execute almost instantly? (unlike the digitalWrite function)
Then measure the width of the pulse on an oscilloscope.
Awwwwww. Will a cheapy one work too? I mean, this one:
http://www.amazon.com/SainSmart-DSO138-1Msps-Digital-Oscilloscope/dp/B00XXZB5LW