Squeakiness and wheel shakes left/right? Wheel Bearing?

I have a 94 z28 that has constant squeaks from the driverside rear. It's been like that since the day I got it. I have replaced the brakes/rotors and checked the calipers and know nothing is causing the squeaking there.

My friend was following me awhile back and said my driverside rear tire looked to be wobbling from left to right, especially when I turned. When I got back, I jacked up the car and made sure the lugs were tight enough. Then I proceeded to try and shake the wheel....and it shook from left to right. It didn't shake much, but there should be no play in that at all!
What would cause this? Wheel bearing? Its just the driverside rear thats making noises and wobbling.
Any insight on this? I am afraid my wheel is going to go shooting off one of these days!:eek:

Okay lets see if I can take a stab at this here.
>>>first take the wheel off and put at least 2 lug nuts on to tighten the rotor to the hub. take the caliper off along with the brake shoes and shake it side to side seeing if the rotor makes any contact to the caliper bracket (holder).
If it does you found your squeak. to fix it you need to get some axle c-clips and get them installed. If you still have contact gm makes a shim kit or you cant do what i did and get some copper brake hose washers and stick them between the caliper bracket and its mount.

Thankyou for your reply...I'm going to take it apart this weekend. Hopefully its just the caliper bracket!