To give you another data point, I got a bunch of 40-watt, 60-watt and 75-watt incandescent bulbs that have been replaced with CFLs rated for 60-watt, 75-watt and 100-watts equivalent of lumens, respectively. Those 100-watt CFLs are incredibly luminous for the 23-watts that they use.
I've also replaced a bunch of older CFLs with new CFLs because the newer bulbs give off a whiter light. I actually prefer them to incandescent now except for the incandescent flood lights that I have -- guess I should look for CFLs for this, but finding flood CFLs that are dimmable as well, I just haven't seen any in the stores.
There is no excuse not to change over given that the energy companies often subsidize the CFL prices so you get each bulb for about $1. The only drawback has been the slow startup time, but this has improved markedly as well and in many applications it is no longer a problem.
The CFLs that I've had have lasted most of the time that I've used them, 4-6 years, except for a few. Dimmable CFLs are great but hard to find; I haven't tried mail order yet.
Overall, maybe I save enough electricity to make up for all the energy consumed running the computer so often
