For those of you who haven't been paying attention, the standard incandescent light bulb, a staple since Thomas Alva Edison came up with the critter and patented it 129 years ago this month, is going the way of the dodo.
Go to Costco to get a package of bulbs and what you see now instead of the old, well, light-bulb shape you grew up with, are spiral glass-tube compact-fluorescents.
The old ones will be around for a while, and I'm guessing you'll be able to buy them, either from hardware stores or on the net from China or wherever for a long time, but the big markets in the U.S. are switching over.
This is a mixed blessing. On the one hand, the new bulbs use less energy, last longer, and they have finally gotten the spectrum to the point that the light they produce doesn't make your house look like the inside of K-Mart on a rainy Sunday afternoon. If everybody switched over, the energy savings would be huge.
On the other hand, they cost more up front, have to be disposed of differently than the old bulbs or they can cause environmental problems due to the mercury they contain, and when you flip the switch, there is a small, but noticeable, lag time before the light comes on.
One can get used to such things, but it is still oddly disquieting to turn on the light and have that ... pause before it flickers on.