While looking through a hole in the drywall, I saw this...
Is this asbestos?
While it looks like fiberglass, you probably don't want to be wrong if you are going to be doing any work on that area. The easiest thing to do is get the material professionally tested. When I was looking into scraping the nasty acousitcal gunk from our ceiling, I sent a small sample to a local testing company (http://www.asbestos.org/sampling/samples.html) and got a pretty quick response (it was asbestos). It's worth the money to be completely sure. It's your (and your family's) health after all.
If you are not going to be dong work on that area, just leave it undisturbed. If asbestos stays where it is, it isn't normally a problem.