I've personally never had one, but I think there is lots of misinformation about them out there. I think a lot of people instantly picture this when they think of a perm: link
but perms have gotten a LOT better since the 80's. I know people who have gotten really amazing perms like this: link
and the best part is that your hair just dries like that. No blow drying, or curling and it even gets rid of frizz! Another thing a lot of people don't seem to know about perms is that they aren't just for making your hair curly. They can permanently straighten it too!
They may seem like a good idea at the time, but personally I will never succumb to one. They can damage your hair pretty badly and I already have more than enough with my straight iron and curling iron for that.
However, it seems to workout great for some. Several of my friends and family members have gotten one and it didn't do much harm. For me, its just a risk I'd rather pass.