alarm_shark.py

# use 24-hour time format!

import time, os, sys

wh, wm = [ int(i) for i in sys.argv[1].split(':') ]

while True:
    hour, minute = list(time.localtime())[3:5]
    if hour >= wh and minute >= wm:
        break # Snap!
    time.sleep(60) # There's no time.snooze()

os.system("open http://tinysong.com/id4j")

you use it like this:

$ python alarm_shark.py 6:45

or maybe like this:

$ python alarm_shark.py 16:00