The energy savings from CFL bulbs is superb and the astounding lifespan of the bulbs is 6 times longer than standard incandescent lights.   Quality does vary based on the manufacturer. 

Here is an example.  Back in March 2002 I installed driveway lights that come on automatically at dusk and shut down at dawn.  The electrician put in standard 60 W incandescent bulbs that seemed to burn out every two or three weeks.  They didn’t last long and the effort required to replace them was almost as irritating as the high-energy usage.  Going to the local Home Depot I tried 9 watt ceiling fan CFL bulbs (40w equivalent) that at the time seemed expensive at around $7 each.  I bought them to avoid the regular replacement of lights and figured they would pay for the additional cost by energy savings.  I had no idea how long they would last but thought even once per year would be a deal.  It is now near the end of 2008 and I have not had to replace any of them. 

Savings have to be in the hundreds of dollars at this point, but the savings in light replacement aggravation is just as good a reason to consider this approach. The total wattage used by my five driveway lights is 9w x 5 bulbs = 45w.   That is compared to 300w with regular 60w bulbs.  Lower wattage incandescent bulbs get much more expensive per bulb.  You can see the savings in electrical usage.

Disposal of CFL Bulbs is problematic, but at this time the lights last long enough that by the time you get around to replacing them there will probably be a recycling method.

Make sure that when you buy the bulbs that you choose the color based on the desired use.  Some are bright white while others replicate the warm white color of standard incandescent bulbs.

Here are some examples.

Bathroom Vanity Lights