There is another belt specifically for the power steering pump on some cars. I know on a 99 neon I had a while back, a belt was squeaking like mad but I couldn't find it. Took it in and turns out it was the power steering belt. $15 part, $85 in labour... So, it could be your power steering pump or the belt itself. Jerv will let you know if golfs have a separate belt for the P/S pump or not...

My A3 has two belts but each drives at least two items; the power steering pump does not have it's own belt. My A2s did not have power steering and I didn't spend much time under the hood of my wife's so I wouldn't know off the top of my head if it has it's own belt. As for the squeal... my Golfs all communicate(d) like R2-D2 only moreso. They squeal, grunt, whistle, and pop plus they occasionally punctuate with odors above and beyond the typical A2/A3 "wet-dog" smell. My A3 groans and makes a disconcerting grinding sound when turned to full-lock but otherwise the steering system is silent, belt and pump. It also whistles on moderate acceleration (like from a red light) due to a cracked downpipe; depending on the pitch it sometimes sounds like a squeal. Any definite squeal from a parked position in my cars has been attributable to poor clutchwork on my part (arthritic knee). Peeling out with studded snows makes funny noises ;) The closest I can get is my ex-Corsica. The alternator had a bad bearing and would make a squealing sound at certain RPMs above idle but below normal cruising RPM; an RPM range usually only encountered when accelerating from a dead stop.