R2D2 power steering noises

[treed2 at u.washington.edu (T. Reed)]

I thought I'd ask about this because it's been bugging me for a while..

A lot of times I drive without music because I like to hear the
sound of the engine.

But when I'm maneuvering around a parking lot at 5-10 mph and I turn the
wheel I often hear this faint whistley-screechy noise. The best way I can
describe it is like the "wheee-oo" part of the "beep boop wheee-oo" noise
that R2D2 makes. It sounds like its coming from the steering column or
rack. Definitely not the tires or anything like that.

So I'm wondering if anyone knows what causes this? It doesn't sound like a
plastic cover rubbing or anything like that.. are there bearings in the
steering column that can wear out and make noises?

-Toby