Turning a CFL on and off in a short period of time will sharply reduce its lifespan. Ideally, they should be left on for a minimum of 15 minutes.
Florescents give me a freaking headache, too!
I have three on 24x7 (two are outside). That gets the longest lifetime out of them. I have a few more that I turn on once in the evening and off when I go to bed. Everything else is incandescent.