My rotational grinding was the wheel hub bearing. I bought a new assembly for <$100 (
http://tinyurl.com/yygycuba) with this one.
The way I confirmed which wheel it was by jacking up the front, then trying to 'shake the wheel' by pushing on the top, pulling on the bottom, and vice-versa.
The 'play' in this was incredibly small, and not much different between my fronts (I didn't have to check the back). I picked the one with 1-2mm of more play and replaced it with a few hours work in the driveway.
You can see how to check for play at 50 seconds in this video,
YouTube.
I used the video above, and the one below to help me complete the job.
YouTube