I used hypnobirthing with my first baby and will absolutely use it again with my second.
While I wouldn't say that my birth was pain-free, it was absolutely manageable. Not once did I feel I needed to ask for an epidural. I worked alone with my techniques, but if you have a birth partner who will use techniques with you, they can help get you into a deeper relaxation that can probably make the pain disappear. My hubby took classes with me, but then never used any deepening techniques with me. (Actually, he read the paper and had a nap

) He thought I was doing fine on my own, which I guess I was. Still, some people experience absolutely no discomfort at all using hypnobirthing, so it is possible!
Hypnobirthing techniques are all about teaching you to relax so that your body can do its work. Even women who have to have a c-section can use the techniques to remain relaxed before and after the surgery.
The breathing and visualization were essential in my birth, and I found the labouring experience peaceful and calm. For most of my labour (until I hit transition) I was almost sleeping, had my eyes closed and breathed and visualized (sometimes listening to my hypnobirthing scripts on mp3 player). After transition I still had my eyes closed and was peaceful, but I was making a growling noise during pushes. I didn't find pushing painful, it was just a very physical experience. One interesting thing about my birth using hypnobirthing was that my total labour was 12 hrs, yet I felt the whole thing only lasted about 5 hrs.
We never bothered with typical birth classes, spent the money on hypnobirthing classes instead and read our What to Expect When You're Expecting book to fill us in on the rest. It was money well spent.