I always liked the Java Timer/TimerTask classes, and found them to be a useful pattern in many applications. Python seems to lack something quite like this, so I implemented something simple in Python to do basically the same thing.
import Timer, time
timer = Timer.Timer()
class MyTask(Timer.TimerTask):
def run(self):
print 'task running; current time is %.3f'%(time.time())
task = MyTask()
timer.schedulePeriodic(task, 1.0)
time.sleep(10.0)