Joe,
Home depot, Wal-mart, harbor freight and big lots is where I've seen the neon and colored cable ties.
Bob,
You could use a water heater timer ($20), or some other heavy duty timer, so that your compressor won't start up at night. I can't think of a 'cheap' way of putting a 15 minute run time on your compressor, a good 20 amp TDOE relay can be $60 plus.
The switch I listed below has a bunch of trips, you could set it so it could only run every other 15 minutes during the normal day.......
(I just kill the 2 20 amp breakers in my shop when I leave)
http://surpluscenter.com/item.asp?UI...8-250&catname=