If I have the code given (that simple Servo example), how can I run that upon the activation of a switch (say a HIGH) and immediately exit out as the switch goes LOW?
If you have the example as shown and you're determined to use interrupts, then you need to add extra conditions to each of the "for" loops to examine the flag you set in your interrupt service routine, and if it is set, then the "for" will exit immediately. Don't forget to qualify the flag with "volatile"
for(pos = 0; pos < 180 && notAborted; pos += 1) // goes from 0 degrees to 179 degrees if not interrupted