This is an EXTREMELY simple little stopwatch class. You can measure wall-clock durations in two ways:

var tt:TickTock = new TickTock();
tt.start();
doSomeWork();
tt.stop();
trace( "That took "+tickTock.elapsedTimeInMilliseconds+" milliesconds" );

or in a more functional, closure-y style:

var tt:TickTock = TickTock.measure( function(){
  doSomeWork();
});
trace( "That took "+tickTock.elapsedTimeInMilliseconds+" milliesconds" );