Mine does the same thing and the truck sounds like the fucking R.M.S. Titanic when I hit the brakes or go over any bumps (no joke!). My truck only has 48K original miles but I'm sure all of the rubber bushings in the front end are toast. I ordered a front end rebuild kit with PolyGraphite bushings from http://www.p-s-t.com/fektvpg.html. I'm sure this will take care of the heinous creaking problem my Sy has. I'll post a follow-up after I get the whole kit installed in a few weeks. That noise is driving me nuts
A great temporary fix (well 2 years for me) has been to just spray all the bushings down with wd40.
it'll at least get rid of the squeaking till you have time to replace them
HTH