I had the exact same symptoms as everyone here...most notably the "chirp" when the compressor engages. Being the genius that I am, I assumed the belt was a hair too loose, so I should tighten it. About a week later, I had no A/C...
I popped the hood to see the idler pulley seized and half-melted, and the belt wearing a hole in the timing cover.
Now I just deal with the chirp, mainly because I don't use the AC much anyway, as it DESTROYS drivability.
The dust it gives off is awfully annoying, though. Makes my car look like a thoroughbred POS. Do not want.
If I didn't need defrost in the winter and on rainy/humid days, I'd toss this handicapped AC system under a train.