weird high pitch pinging noise?

[spdracer@mail.utexas.edu]

I got home from a drive tonight and noticed a weird metallic high pitch pinging
noise that hadn't been there before as I was pulling into my parking space.  I
tried to find the source and it seems to be coming from kinda down low near the
turbo.  It only seems to occur at idle and it only happens every 10 or so
seconds.  My oil pressure and oil level are fine, didn't rev past 7k, stock
boost pressure, and I've driven the car a lot harder than this before.  I never
heard any detonation (though I'm not positive I know what detonation sounds
like).

Possible spun bearing?  I need to change the oil soon so I'll be poking around
the engine some.

Khiem