Squeaking noise from under bed

I have an 08 Tacoma. Bought it last June 2012. Recently ive noticed a squeaking kinda noise coming from the rear.. My mechanic friend told me it may be bushings?? Im not a mechanic at all. Another friend told me it may be my shocks, he specified "inside" the shocks.. It happens whenever I go over the littlest bump and even when I go to get out of me truck ( Im a large guy). I sprayed white lithium grease everywhere around the rubber parts and it still does it. It however doesnt squeak when its raining or has rained.. Anyone else have this issue or can give me any input? Thanks!

 

Its the leaf springs. My 06 does it. The bushings need to be replaced. Its an easy fix that you can do yourself.

 

^^ X2. Very common symptom with leaf springs. Many people experience this. Might want to use a stethoscope to confirm:
Some have luck spraying chain lube (I do this method). There is a write-up using rubber pads or other material between the leaves as well.