Been using one for about a year now with a nasal mask (not pillows). No humidifier, but I live in Oregon, and we've got plenty of humidity.
Originally posted by Sandman
Never heard of it... what does it do?
For OSA (Obstructive Sleep Apnea), it pressurizes your airway to keep the tissue from collapsing when the muscles around your throat relax while sleeping. Generally, the cause of this is being a big fat fatty, and the result is that you don't ever really get enough uninterrupted REM, and you don't go through the sleep states like normal people. Basically, an Apnea is when you stop breathing. When this happens, your brain gets uppity and forces you to wake up...generally not fully concious, just enough to conciously take a breath. Then you go back to sleep and the whole cycle repeats itself. When I was tested, I had an apnea an average of every 45 seconds while sleeping. The machine is a wonder, I'd actually be getting full nights of sleep were it not for school, and I get to look like a fighter pilot while I am sleeping (I just need to get myself a helmet)!

-edit- Oh, and it eliminates the snoring too, which is a side effect of OSA. And by snoring, I mean snarling and grunting like an angry bear fighting a cougar.