There called D bushings because there shaped like a D, you should have the truck on the ground or on ramps when unbolting them, jacking It up will put pressure on the sway bar. the bushings have a cut in them so they can just slide off the sway bar, they should be removed and greased inside where they go around the sway bar (doesn't hurt to put grease on the bar it 'self in the same spot) and put back on, it's a 10-15 minute job, when you put the bolts back in put some blue threadlock on them so they don't work there way loose down the road.
Ok much thanks for the info. When I get a chance I'll do this, I will; it's just that it started raining (and yes, it sqwaks in the rain too). I wanted to know if it was a sway bar bushing (rear) or a sway bar bushing to frame, because all the vendors specify one or the other, and I don't know which one to get if I want to replace it.
Yesterday, I found this:
http://www.tahoeyukonforum.com/threads/stopping-07-tahoe-creak.3437/#post-221691
I went outside in the evening, and applied dielectric grease to all the weatherstripping.
What do you know: it made it 100% better!!! It did not eliminate it completely, but it made it a ton, ton better. It doesn't creak on every single bump. Maybe a major bump it'll creak lightly, but no more squeak/creak all over the place.
I might be onto something here, so I may wipe it down and reapply again, and this time do the sunroof as well.