You can get the compact flourescent bulbs for things like vanity fixtures & other special types, but they cost alot, and don't always fit. I did get some nice round ones for our kitchen fixture, but they defintely cost more than the spiral ones. Also, sometimes the special shaped ones don't fit. For example, I got some 3 way ones for our living room lamps, and they were way too tall, so I had to return them. Also, I bought some for my sons recessed lights (about $10 each), and they didn't fit either. I did take a pliers to modify the light housing to make one fit, but I gave up on making the others fit.
I did go ahead and replace any light that could take the regular spiral compact flourescents because they don't cost quite as much, and I gave the old ones to my mom, but I'm waiting on the special shaped ones. I still have to replace the bathroom vanity bulbs, and I'm going to wait until they burn our first, just because they cost so much more.
I think you can get a 6 pack of spiral ones for $10 or less, so that's a pretty good deal.