I hadn't heard this before, but here is witness 8 talking to Crump over the phone.
http://abcnews.go.com/US/video/hear-phone-conversation-18622033
Her story tracks very well with the know evidence, all the way down to what the weather was like, how Trayvon adjusted his hoodie, and a description of the phone being knocked down at the start of the fight (which again, matches the flashlight's location, which supports the idea that the fight started where Trayvon was murdered). And unlike George, she wasn't even there and had never been to those houses in her life. Yet she describes the scene very well.
Interestingly, she speaks much better in this recording than when she was talking to BLDR. I suspect she gets very nervous around authority.