I just threw together a really straightforward stopwatch class, for use when profiling operations in ActionScript code. You can either use it in an old-skool procedural way:

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

or in a fancy-pants, functional, closure-y way:

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

Being primarily a ruby guy, I prefer the fancy-pants approach ;) The class, along with a little sample app, is up on GitHub now.